sagemathgh-38390: simplify some iterations (ruff PERF102)

    
this is simplifying some iterations, and was scripted using `ruff`

### 📝 Checklist

- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.
    
URL: sagemath#38390
Reported by: Frédéric Chapoton
Reviewer(s): David Coudert

src/sage/categories/pushout.py

@@ -1985,12 +1985,12 @@ def _apply_functor(self, R):
         name = self.name_mapping.get(R, None)
         latex_name = self.latex_name_mapping.get(R, None)
         if name is None:
-            for base_ring, name in self.name_mapping.items():
+            for name in self.name_mapping.values():
                 name = f'{name}_base_ext'
                 break
         if latex_name is None:
             from sage.misc.latex import latex
-            for base_ring, latex_name in self.latex_name_mapping.items():
+            for latex_name in self.latex_name_mapping.values():
                 latex_name = fr'{latex_name} \otimes {latex(R)}'
                 break
         if name is None and latex_name is None:

src/sage/manifolds/differentiable/scalarfield.py

@@ -689,7 +689,7 @@ def _del_derived(self):
         ScalarField._del_derived(self) # derived quantities of the mother class
         self._differential = None  # reset of the differential
         # First deletes any reference to self in the vectors' dictionaries:
-        for vid, val in self._lie_derivatives.items():
+        for val in self._lie_derivatives.values():
             del val[0]._lie_der_along_self[id(self)]
         # Then clears the dictionary of Lie derivatives
         self._lie_derivatives.clear()

src/sage/manifolds/differentiable/tensorfield.py

@@ -708,7 +708,7 @@ def _del_derived(self):
 
         """
         # First deletes any reference to self in the vectors' dictionaries:
-        for vid, val in self._lie_derivatives.items():
+        for val in self._lie_derivatives.values():
             del val[0]._lie_der_along_self[id(self)]
         # Then clears the dictionary of Lie derivatives
         self._lie_derivatives.clear()

src/sage/manifolds/differentiable/vectorfield.py

@@ -300,7 +300,7 @@ def _del_dependencies(self):
 
         """
         if self._lie_der_along_self != {}:
-            for idtens, tens in self._lie_der_along_self.items():
+            for tens in self._lie_der_along_self.values():
                 del tens._lie_derivatives[id(self)]
             self._lie_der_along_self.clear()
 

src/sage/repl/rich_output/preferences.py

@@ -368,7 +368,7 @@ def available_options(self):
             (align_latex, graphics, supplemental_plot, text)
         """
         options = []
-        for key, value in self.__class__.__dict__.items():
+        for value in self.__class__.__dict__.values():
             if isinstance(value, Property):
                 options.append(value)
         return tuple(sorted(options, key=str))

src/sage/rings/finite_rings/conway_polynomials.py

@@ -433,7 +433,7 @@ def _frobenius_shift(K, generators, check_only=False):
                 q, x = compatible[m].popitem()
             except KeyError:
                 break
-            for qq, xx in compatible[m].items():
+            for xx in compatible[m].values():
                 assert x == xx
         return
     crt = {}