refactor: move go-chi/cache into Gitea (#39530)

The `gitea.com/go-chi/cache` package only exists for Gitea, so it moves
into `modules/cache`.

- `ITEM_TTL = -1` disables caching as documented
- Sub-second TTLs round up instead of never expiring
- The Redis adapter no longer grows a `MacaronCache` hash
- Use two-queue cache for in-memory cache

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/git/last_commit_cache.go

@@ -25,14 +25,20 @@ type LastCommitCache struct {
 
 // Put puts the last commit id with commit and entry path
 func (c *LastCommitCache) Put(ref, entryPath, commitID string) error {
+	if c.ttlFn() < 0 {
+		return nil
+	}
 	log.Debug("LastCommitCache save: [%s:%s:%s]", ref, entryPath, commitID)
 	return c.cache.Put(getCacheKey(c.repo, ref, entryPath), commitID, c.ttlFn())
 }
 
 // Get gets the last commit information by commit id and entry path
 func (c *LastCommitCache) Get(ctx context.Context, ref, entryPath string) (*Commit, error) {
-	lastCommitID, ok := c.cache.Get(getCacheKey(c.repo, ref, entryPath))
-	if !ok || lastCommitID == "" {
+	var lastCommitID string
+	if c.ttlFn() >= 0 {
+		lastCommitID, _ = c.cache.Get(getCacheKey(c.repo, ref, entryPath))
+	}
+	if lastCommitID == "" {
 		return nil, nil //nolint:nilnil // return nil when cache miss
 	}