feat!: Remove metrics API from the JS SDK (#14745)

1. Removes `metrics` export and all it's usages
2. Removes all usages of `_metrics_summary` from the SDK
3. Removes `metricsShim` usage in the browser SDK CDN bundles
4. Removes all metrics related types from the SDK

Author: AbhiPrasad

Diff for: dev-packages/browser-integration-tests/suites/metrics/metricsEvent/init.js

@@ -270,18 +270,6 @@ export function shouldSkipFeedbackTest(): boolean {
   return false;
 }
 
-/**
- * We can only test metrics tests in certain bundles/packages:
- * - NPM (ESM, CJS)
- * - CDN bundles that include tracing
- *
- * @returns `true` if we should skip the metrics test
- */
-export function shouldSkipMetricsTest(): boolean {
-  const bundle = process.env.PW_BUNDLE as string | undefined;
-  return bundle != null && !bundle.includes('tracing') && !bundle.includes('esm') && !bundle.includes('cjs');
-}
-
 /**
  * We only test feature flags integrations in certain bundles/packages:
  * - NPM (ESM, CJS)