sage.misc.dev_tools.find_objects_from_name: use a copy of sys.modules

In an attempt to avoid the following error on the CI...

  dt.find_objects_from_name('FareySymbol')
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/sage/src/sage/misc/dev_tools.py", line 279,
  in find_objects_from_name
    for smodule_name, smodule in sys.modules.items():
  RuntimeError: dictionary changed size during iteration

we make a copy of the sys.modules dict before iterating over its
items.

Author: orlitzky

src/sage/misc/dev_tools.py

@@ -275,8 +275,12 @@ def find_objects_from_name(name, module_name=None, include_lazy_imports=False):
     """
     from sage.misc.lazy_import import LazyImport
 
+    # Create a copy to avoid errors if the sys.modules dict changes
+    # while we are iterating over it.
+    mods = sys.modules.copy()
+
     obj = []
-    for smodule_name, smodule in sys.modules.items():
+    for smodule_name, smodule in mods.items():
         if module_name and not smodule_name.startswith(module_name):
             continue
         if hasattr(smodule, '__dict__') and name in smodule.__dict__: