fix: add missing return statement from deprecated 'for()' method (#49)

Follow-up PR from #46. Forgot to return from the deprecated method.

Reviewed-on: https://codeberg.org/vlw/php-mysql/pulls/49

src/MySQL.php

@@ -81,7 +81,7 @@
 			since: "3.5.7",
 		)]
 		public function for(string $table): self {
-			$this->from($table);
+			return $this->from($table);
 		}
 
 		// Create a WHERE statement from filters