fix(deps): update dependency @aws-lambda-powertools/metrics to ^2.15.0 (#68)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package-lock.json

@@ -81,7 +81,7 @@
   ],
   "prettier": "@bifravst/prettier-config",
   "peerDependencies": {
-    "@aws-lambda-powertools/metrics": "^2.14.0",
+    "@aws-lambda-powertools/metrics": "^2.15.0",
     "@hello.nrfcloud.com/proto": "^15.3.57",
     "@middy/core": "^6.0.0",
     "@middy/input-output-logger": "^6.0.0"