chore: bump flagd provider's flagd-core dep to ^4.0.0

Signed-off-by: Todd Baert <todd.baert@dynatrace.com>

Author: toddbaert

libs/providers/flagd/package.json

@@ -17,6 +17,6 @@
   },
   "dependencies": {
     "lru-cache": "^11.0.0",
-    "@openfeature/flagd-core": "^3.0.0"
+    "@openfeature/flagd-core": "^4.0.0"
   }
 }