Revert "Add GitHub action for labelling PRs"

This reverts commit 0ff13dcf.

src/chunklist.go

@@ -99,21 +99,6 @@ func (cl *ChunkList) Clear() {
 	cl.mutex.Unlock()
 }
 
-// Retransform iterates all items and applies fn to each one.
-// The done callback runs under the lock to safely update shared state.
-func (cl *ChunkList) Retransform(fn func(*Item), done func()) {
-	cl.mutex.Lock()
-	for _, chunk := range cl.chunks {
-		for i := 0; i < chunk.count; i++ {
-			fn(&chunk.items[i])
-		}
-	}
-	if done != nil {
-		done()
-	}
-	cl.mutex.Unlock()
-}
-
 // Snapshot returns immutable snapshot of the ChunkList
 func (cl *ChunkList) Snapshot(tail int) ([]*Chunk, int, bool) {
 	cl.mutex.Lock()