Merge branch 'ob/more-repo-config-values'

Merge branch 'ob/more-repo-config-values'

Many core configuration variables have been migrated from global
variables into 'repo_config_values' to tie them to a specific
repository instance, avoiding cross-repository state leakage.

* ob/more-repo-config-values:
  environment: move "warn_on_object_refname_ambiguity" into `struct repo_config_values`
  environment: move "sparse_expect_files_outside_of_patterns" into `struct repo_config_values`
  environment: move "core_sparse_checkout_cone" into `struct repo_config_values`
  environment: move "precomposed_unicode" into `struct repo_config_values`
  environment: move "pack_compression_level" into `struct repo_config_values`
  environment: move `zlib_compression_level` into `struct repo_config_values`
  environment: move "check_stat" into `struct repo_config_values`
  environment: move "trust_ctime" into `struct repo_config_values`