gh-35409: fix pep8 E303 in folders starting with m
    
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### 📚 Description

fix all pep8 E303 warning in the folders whose name starts with the
letter m

purely done with autopep8:

```
$ autopep8 -i --select=E303 src/sage/m*/*.py
$ autopep8 -i --select=E303 src/sage/m*/*/*.py
```

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### ⌛ Dependencies

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URL: #35409
Reported by: Frédéric Chapoton
Reviewer(s): David Coudert

Author: Release Manager

src/sage/manifolds/chart.py

@@ -2317,7 +2317,6 @@ def _tighten_bounds(self):
         self._restrictions = new_restrictions
         self._fast_valid_coordinates = None
 
-
     def restrict(self, subset, restrictions=None):
         r"""
         Return the restriction of the chart to some open subset of its domain.

src/sage/manifolds/differentiable/automorphismfield_group.py

@@ -175,7 +175,6 @@ def __init__(self, vector_field_module):
         Parent.__init__(self, category=Groups())
         self._vmodule = vector_field_module
 
-
     #### Parent methods ####
 
     def _element_constructor_(self, comp=[], frame=None, name=None,
@@ -266,7 +265,6 @@ def _an_element_(self):
 
     #### End of parent methods ####
 
-
     #### Monoid methods ####
 
     @cached_method

src/sage/manifolds/differentiable/chart.py

@@ -679,7 +679,6 @@ def symbolic_velocities(self, left='D', right=None):
         return list(var(list_strings_velocities))
 
 
-
 #*****************************************************************************
 
 class RealDiffChart(DiffChart, RealChart):
@@ -1001,7 +1000,6 @@ def __init__(self, domain, coordinates, calc_method=None,
         self._frame = CoordFrame(self)
         self._coframe = self._frame._coframe
 
-
     def restrict(self, subset, restrictions=None):
         r"""
         Return the restriction of the chart to some subset.

src/sage/manifolds/differentiable/degenerate.py

@@ -368,7 +368,6 @@ def open_subset(self, name, latex_name=None, coord_def={}):
         return resu
 
 
-
 #*******************************************************************************************
 
 from sage.manifolds.differentiable.tensorfield_paral import TensorFieldParal

src/sage/manifolds/differentiable/degenerate_submanifold.py

@@ -1323,7 +1323,6 @@ def principal_directions(self, screen=None):
         self._principal_directions[screen._name] = res
         return res
 
-
     def mean_curvature(self, screen=None):
         r"""
 

src/sage/manifolds/differentiable/diff_form.py

@@ -1556,7 +1556,6 @@ def wedge(self, other):
         other_r = other.restrict(dom_resu)
         return FreeModuleAltForm.wedge(self_r, other_r)
 
-
     def interior_product(self, qvect):
         r"""
         Interior product with a multivector field.

src/sage/manifolds/differentiable/diff_map.py

@@ -1144,7 +1144,6 @@ def paral_comp(tcomp, chart1, chart2, coord2_1, jacob,
                             resu._components[frame] = comp
         return resu
 
-
     def pushforward(self, tensor):
         r"""
         Pushforward operator associated with ``self``.

src/sage/manifolds/differentiable/integrated_curve.py

@@ -579,7 +579,6 @@ def fast_CoF(pos, vel, M=M):
                                for f in transf]
                 self._fast_changes_of_chart[CoC] = fast_transf
 
-
         self._velocities = list(velocities) # converts to list
         # since might not already be a list (which is later required)
         self._curve_parameter = curve_parameter
@@ -1376,13 +1375,11 @@ def jacobian(t,y):
         # 'tangent_vector_eval_at', and in 'plot' when plotting the
         # tangent vectors.)
 
-
         if isinstance(sol, list):
             coords_sol = [point[0:dim + 1] for point in sol]
         else:
             coords_sol = sol[:, 0:dim + 1].tolist() # far faster in numpy
 
-
         if verbose:
             print("Numerical integration completed.\n\n" +
                   "Checking all points are in the chart domain...")
@@ -1779,7 +1776,6 @@ def solve_across_charts(self, charts=None, step=None, solution_key=None,
                             new_vel = self._fast_changes_of_frame[(new_chart.frame().restrict(inter),
                                chart.frame().restrict(inter))](last_pts, last_vel)
 
-
                             ics = new_pts + new_vel
                             chart = new_chart
 
@@ -2434,7 +2430,6 @@ def plot_integrated(self, chart=None, ambient_coords=None,
         thickness = kwds.pop('thickness')
         aspect_ratio = kwds.pop('aspect_ratio')
 
-
         #
         # The mapping, if present, and the chart with respect to which the curve
         # is plotted
@@ -3425,7 +3420,6 @@ def __init__(self, parent, affine_connection, curve_parameter,
 
         velocities = chart.symbolic_velocities()
 
-
         dim = parent.codomain().dim()
         i0 = parent.codomain().start_index()
 
@@ -3470,7 +3464,6 @@ def __init__(self, parent, affine_connection, curve_parameter,
                     equations_rhs_chart += [rhs.simplify_full()]
                 equations_rhs[chart] = equations_rhs_chart
 
-
         IntegratedCurve.__init__(self, parent, equations_rhs,
                                  velocities, curve_parameter,
                                  initial_tangent_vector, chart=chart,
@@ -3479,7 +3472,6 @@ def __init__(self, parent, affine_connection, curve_parameter,
 
         self._affine_connection = affine_connection
 
-
     def _repr_(self):
         r"""
         Return a string representation of ``self``.
@@ -3825,7 +3817,6 @@ class IntegratedGeodesic(IntegratedAutoparallelCurve):
     def __init__(self, parent, metric, curve_parameter,
                  initial_tangent_vector, chart=None, name=None,
                  latex_name=None, verbose=False, across_charts=False):
-
         r"""
         Construct a geodesic curve with respect to the given metric with the
         given initial tangent vector.

src/sage/manifolds/differentiable/levi_civita_connection.py

@@ -387,7 +387,6 @@ def _new_coef(self, frame):
                               start_index=self._domain._sindex,
                               output_formatter=DiffScalarField.coord_function)
 
-
     def coef(self, frame=None):
         r"""
         Return the connection coefficients relative to the given frame.

src/sage/manifolds/differentiable/manifold.py

@@ -2977,7 +2977,6 @@ def change_of_frame(self, frame1, frame2):
                              " has not been defined on the {}".format(self))
         return self._frame_changes[(frame1, frame2)]
 
-
     def set_change_of_frame(self, frame1, frame2, change_of_frame,
                          compute_inverse=True):
         r"""