[GH-19267] Spelling comments (#19268)

* spelling: comments

Signed-off-by: Josh Soref <jsoref@users.noreply.github.com>
Co-authored-by: Josh Soref <jsoref@users.noreply.github.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

app/file.go

@@ -648,7 +648,7 @@ type UploadFileTask struct {
 	imageType        string
 	imageOrientation int
 
-	// Testing: overrideable dependency functions
+	// Testing: overridable dependency functions
 	pluginsEnvironment *plugin.Environment
 	writeFile          func(io.Reader, string) (int64, *model.AppError)
 	saveToDatabase     func(*model.FileInfo) (*model.FileInfo, error)