chore: downgrade prometheus so its usable in our api (#105)

Author: lan17

poetry.lock

@@ -31,7 +31,7 @@ repository = "https://github.com/rungalileo/gcache"
 [tool.poetry.dependencies]
 python = "^3.10"
 pydantic = "^2.11.4"
-prometheus-client = "^0.23.1"
+prometheus-client = "^0.22.1"
 cachetools = ">=5.5.2"
 types-cachetools = "^6.2.0.20250827"
 redis = ">=5.0.0"