Revert prefactor m in autograd documentation (#3221)

The prefactor m was incorrectly added to the vector-Jacobian product formula in the autograd tutorial. This change was based on the mistaken assumption that m-scaling was necessary to account for multiple terms in the summation. However, the chain rule and vector-Jacobian product formula already correctly aggregate contributions from all intermediate variables without requiring explicit scaling by m.

Author: asideofcode-dev

beginner_source/blitz/autograd_tutorial.py

@@ -191,15 +191,15 @@
 # .. math::
 #
 #
-#      J^{T}\cdot \vec{v} = m \cdot \left(\begin{array}{ccc}
+#      J^{T}\cdot \vec{v} = \left(\begin{array}{ccc}
 #       \frac{\partial y_{1}}{\partial x_{1}} & \cdots & \frac{\partial y_{m}}{\partial x_{1}}\\
 #       \vdots & \ddots & \vdots\\
 #       \frac{\partial y_{1}}{\partial x_{n}} & \cdots & \frac{\partial y_{m}}{\partial x_{n}}
 #       \end{array}\right)\left(\begin{array}{c}
 #       \frac{\partial l}{\partial y_{1}}\\
 #       \vdots\\
 #       \frac{\partial l}{\partial y_{m}}
-#       \end{array}\right) = m \cdot \left(\begin{array}{c}
+#       \end{array}\right) = \left(\begin{array}{c}
 #       \frac{\partial l}{\partial x_{1}}\\
 #       \vdots\\
 #       \frac{\partial l}{\partial x_{n}}