Make SR doctests optional in sage.tensor.modules (#32712)

Author: egourgoulhon

src/sage/tensor/modules/comp.py

@@ -1168,9 +1168,9 @@ def display(self, symbol, latex_symbol=None, index_positions=None,
 
         Check that the bug reported in :trac:`22520` is fixed::
 
-            sage: c = Components(SR, [1, 2], 1)
-            sage: c[0] = SR.var('t', domain='real')
-            sage: c.display('c')
+            sage: c = Components(SR, [1, 2], 1)      # optional - sage.symbolic
+            sage: c[0] = SR.var('t', domain='real')  # optional - sage.symbolic
+            sage: c.display('c')                     # optional - sage.symbolic
             c_0 = t
 
         """

src/sage/tensor/modules/free_module_alt_form.py

@@ -554,11 +554,11 @@ def display(self, basis=None, format_spec=None):
 
         Check that the bug reported in :trac:`22520` is fixed::
 
-            sage: M = FiniteRankFreeModule(SR, 2, name='M')
-            sage: e = M.basis('e')
-            sage: a = M.alternating_form(2)
-            sage: a[0,1] = SR.var('t', domain='real')
-            sage: a.display()
+            sage: M = FiniteRankFreeModule(SR, 2, name='M')  # optional - sage.symbolic
+            sage: e = M.basis('e')                           # optional - sage.symbolic
+            sage: a = M.alternating_form(2)                  # optional - sage.symbolic
+            sage: a[0,1] = SR.var('t', domain='real')        # optional - sage.symbolic
+            sage: a.display()                                # optional - sage.symbolic
             t e^0∧e^1
 
         """

src/sage/tensor/modules/free_module_tensor.py

@@ -687,10 +687,10 @@ def display(self, basis=None, format_spec=None):
 
         Check that the bug reported in :trac:`22520` is fixed::
 
-            sage: M = FiniteRankFreeModule(SR, 3, name='M')
-            sage: e = M.basis('e')
-            sage: t = SR.var('t', domain='real')
-            sage: (t*e[0]).display()
+            sage: M = FiniteRankFreeModule(SR, 3, name='M')  # optional - sage.symbolic
+            sage: e = M.basis('e')                           # optional - sage.symbolic
+            sage: t = SR.var('t', domain='real')             # optional - sage.symbolic
+            sage: (t*e[0]).display()                         # optional - sage.symbolic
             t e_0
 
         """