Make deltas system correctly handle submodules in repository under test

The deltas system must use `git checkout --recurse_submodules` when checking out the base and head refs so the submodule is always at the ref corresponding to the superproject's ref.

Author: per1234

compilesketches/compilesketches.py

@@ -813,7 +813,7 @@ def get_sketch_report(self, compilation_result):
             previous_compilation_result = self.compile_sketch(sketch_path=compilation_result.sketch)
 
             # git checkout the head ref to return the repository to its previous state
-            repository.git.checkout(original_git_ref)
+            repository.git.checkout(original_git_ref, recurse_submodules=True)
 
             previous_sizes = self.get_sizes_from_output(compilation_result=previous_compilation_result)
 
@@ -940,11 +940,15 @@ def checkout_deltas_base_ref(self):
 
         # git fetch the deltas base ref
         origin_remote = repository.remotes["origin"]
-        origin_remote.fetch(refspec=self.deltas_base_ref, verbose=self.verbose, no_tags=True, prune=True,
-                            depth=1)
+        origin_remote.fetch(refspec=self.deltas_base_ref,
+                            verbose=self.verbose,
+                            no_tags=True,
+                            prune=True,
+                            depth=1,
+                            recurse_submodules=True)
 
         # git checkout the deltas base ref
-        repository.git.checkout(self.deltas_base_ref)
+        repository.git.checkout(self.deltas_base_ref, recurse_submodules=True)
 
     def get_sizes_report(self, current_sizes, previous_sizes):
         """Return a list containing all memory usage data assembled.

compilesketches/tests/test_compilesketches.py

@@ -1267,7 +1267,7 @@ def checkout(self):
         git.Repo.assert_called_once_with(path=os.environ["GITHUB_WORKSPACE"])
         compile_sketches.checkout_deltas_base_ref.assert_called_once()
         compile_sketches.compile_sketch.assert_called_once_with(compile_sketches, sketch_path=compilation_result.sketch)
-        Repo.checkout.assert_called_once_with(original_git_ref)
+        Repo.checkout.assert_called_once_with(original_git_ref, recurse_submodules=True)
         get_sizes_from_output_calls.append(
             unittest.mock.call(compile_sketches, compilation_result=previous_compilation_result))
         expected_previous_sizes = sizes_list[1]
@@ -1549,9 +1549,11 @@ def checkout(self):
     git.Repo.assert_called_once_with(path=os.environ["GITHUB_WORKSPACE"])
     Repo.fetch.assert_called_once_with(refspec=deltas_base_ref,
                                        verbose=compile_sketches.verbose,
-                                       no_tags=True, prune=True,
-                                       depth=1)
-    Repo.checkout.assert_called_once_with(deltas_base_ref)
+                                       no_tags=True,
+                                       prune=True,
+                                       depth=1,
+                                       recurse_submodules=True)
+    Repo.checkout.assert_called_once_with(deltas_base_ref, recurse_submodules=True)
 
 
 def test_get_sizes_report(mocker):