repository.h: drop unused `gc_cruft_packs`

As of the previous commit, all callers that need to read the value of
`gc.cruftPacks` do so outside without using the `repo_settings` struct,
making its `gc_cruft_packs` unused. Drop it accordingly.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

repo-settings.c

@@ -41,10 +41,8 @@ void prepare_repo_settings(struct repository *r)
 	repo_cfg_bool(r, "feature.experimental", &experimental, 0);
 
 	/* Defaults modified by feature.* */
-	if (experimental) {
+	if (experimental)
 		r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING;
-		r->settings.gc_cruft_packs = 1;
-	}
 	if (manyfiles) {
 		r->settings.index_version = 4;
 		r->settings.index_skip_hash = 1;

repository.h

@@ -33,7 +33,6 @@ struct repo_settings {
 	int commit_graph_generation_version;
 	int commit_graph_read_changed_paths;
 	int gc_write_commit_graph;
-	int gc_cruft_packs;
 	int fetch_write_commit_graph;
 	int command_requires_full_index;
 	int sparse_index;