Merge branch 'ps/environ-wo-the-repository'

Code clean-up.

* ps/environ-wo-the-repository: (21 commits)
  environment: stop storing "core.notesRef" globally
  environment: stop storing "core.warnAmbiguousRefs" globally
  environment: stop storing "core.preferSymlinkRefs" globally
  environment: stop storing "core.logAllRefUpdates" globally
  refs: stop modifying global `log_all_ref_updates` variable
  branch: stop modifying `log_all_ref_updates` variable
  repo-settings: track defaults close to `struct repo_settings`
  repo-settings: split out declarations into a standalone header
  environment: guard state depending on a repository
  environment: reorder header to split out `the_repository`-free section
  environment: move `set_git_dir()` and related into setup layer
  environment: make `get_git_namespace()` self-contained
  environment: move object database functions into object layer
  config: make dependency on repo in `read_early_config()` explicit
  config: document `read_early_config()` and `read_very_early_config()`
  environment: make `get_git_work_tree()` accept a repository
  environment: make `get_graft_file()` accept a repository
  environment: make `get_index_file()` accept a repository
  environment: make `get_object_directory()` accept a repository
  environment: make `get_git_common_dir()` accept a repository
  ...

submodule.c

@@ -2464,7 +2464,7 @@ void absorb_git_dir_into_superproject(const char *path,
 	} else {
 		/* Is it already absorbed into the superprojects git dir? */
 		char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
-		char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
+		char *real_common_git_dir = real_pathdup(repo_get_common_dir(the_repository), 1);
 
 		if (!starts_with(real_sub_git_dir, real_common_git_dir))
 			relocate_single_git_dir_into_superproject(path, super_prefix);