[misc] bump metrics module to 3.4.1

- renamed package from `metrics-sharelatex` to `@overleaf/metrics`
- drop support for statsd backend
- decaffeinate
- compress `/metrics` response using gzip
- bump debugging agents to latest versions
- expose prometheus interfaces for custom metrics (custom tags)
- cleanup of open sockets metrics
- fix deprecation warnings for header access

services/docstore/package.json

@@ -19,7 +19,7 @@
     "format:fix": "node_modules/.bin/prettier-eslint $PWD'/**/*.js' --write"
   },
   "dependencies": {
-    "@overleaf/metrics": "^3.1.0",
+    "@overleaf/metrics": "^3.4.1",
     "@overleaf/object-persistor": "git+https://github.com/overleaf/object-persistor.git",
     "async": "^2.6.3",
     "body-parser": "^1.19.0",