Fix various documentation, user-facing, and source comment typos (#16367)

* Fix various doc, user-facing, and source comment typos

Found via `codespell -q 3 -S ./options/locale,./vendor -L ba,pullrequest,pullrequests,readby`

modules/git/utils.go

@@ -13,7 +13,7 @@ import (
 	"sync"
 )
 
-// ObjectCache provides thread-safe cache opeations.
+// ObjectCache provides thread-safe cache operations.
 type ObjectCache struct {
 	lock  sync.RWMutex
 	cache map[string]interface{}