chore: enable forcetypeassert linter, fix issues (#38804)

Enable [`forcetypeassert`](https://github.com/gostaticanalysis/forcetypeassert)
linter to prevent unchecked type assertions. ~650 issues fixed, most
fixes were clean, some use `setting.PanicInDevOrTesting`.

The only behaviour changes are where code would previously send a 500 error
or panic, a 4xx error is now emitted.

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

routers/api/actions/artifacts_chunks.go

@@ -323,7 +323,7 @@ func mergeChunksForArtifact(ctx *ArtifactContext, chunks []*chunkFileItem, st st
 	readers := make([]io.Reader, 0, len(allChunks))
 	closeReaders := func() {
 		for _, r := range readers {
-			_ = r.(io.Closer).Close() // it guarantees to be io.Closer by the following loop's Open function
+			_ = r.(io.Closer).Close() //nolint:forcetypeassert // it guarantees to be io.Closer by the following loop's Open function
 		}
 		readers = nil
 	}