Add type annotations for new methods

Author: remyoudompheng

src/flint/types/nmod_poly.pyi

@@ -27,6 +27,7 @@ class nmod_poly(flint_poly[nmod]):
     def is_constant(self) -> bool: ...
     def is_gen(self) -> bool: ...
     def reverse(self, degree: int | None = None) -> nmod_poly: ...
+    def truncate(self, n: int) -> nmod_poly: ...
     def leading_coefficient(self) -> nmod: ...
     def inverse_series_trunc(self, n: int) -> nmod_poly: ...
     def compose(self, other: inmod_poly) -> nmod_poly: ...
@@ -53,6 +54,8 @@ class nmod_poly(flint_poly[nmod]):
     def __rmod__(self, other: inmod_poly) -> nmod_poly: ...
     def __divmod__(self, other: inmod_poly) -> tuple[nmod_poly, nmod_poly]: ...
     def __rdivmod__(self, other: inmod_poly) -> tuple[nmod_poly, nmod_poly]: ...
+    def left_shift(self, n: int) -> nmod_poly: ...
+    def right_shift(self, n: int) -> nmod_poly: ...
     def __pow__(self, other: int, mod: inmod_poly | None = None) -> nmod_poly: ...
     def pow_mod(
         self, e: int, modulus: inmod_poly, mod_rev_inv: inmod_poly | None = None