Fix image stuttering (#3035)

* Fix image stuttering.

* Fix docker publishing for PRs

* Write tests for new square parameter.

* Simplify code for createImage.

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Co-authored-by: Deluan Quintão <deluan@navidrome.org>

core/artwork/cache_warmer.go

@@ -129,7 +129,7 @@ func (a *cacheWarmer) doCacheImage(ctx context.Context, id model.ArtworkID) erro
 	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
 
-	r, _, err := a.artwork.Get(ctx, id, consts.UICoverArtSize)
+	r, _, err := a.artwork.Get(ctx, id, consts.UICoverArtSize, false)
 	if err != nil {
 		return fmt.Errorf("error caching id='%s': %w", id, err)
 	}