fix: Update felixfbecker/language-server from v5.1.0 to v5.1.1 (#218)

Author: dependencies[bot]

composer.json

@@ -2,7 +2,7 @@
     "minimum-stability": "dev",
     "prefer-stable": true,
     "require": {
-        "felixfbecker/language-server": "^5.0.0"
+        "felixfbecker/language-server": "v5.1.1"
     },
     "scripts": {
         "parse-stubs": "LanguageServer\\ComposerScripts::parseStubs",