fix(core): Stop awaiting build start telemetry to avoid breaking module federation builds (#818)

* fix(core): Stop awaiting build start telemetry to avoid breaking module
federation builds

Prior to this fix, we would create a span when the build starts and await
flushing it before proceeding with the build. This breaks when using module
federation builds as outlined in #816.

This fix removes the blocking await and optimistically fires off the span. This
**should** be fine as we definitely care more about not breaking user builds
than telemetry arriving. It could lead to us potentially missing this span
sometimes when builds run very fast and finish before the span flushes out,
however given that the build process usually takes longer (especially when
sourcemaps and uploading sourcemaps is involved) it should be fine most of the
time.

Closes: #816

* Update packages/bundler-plugin-core/src/index.ts

Co-authored-by: Jan Peer Stöcklmair <jan.oster94@gmail.com>

---------

Co-authored-by: Jan Peer Stöcklmair <jan.oster94@gmail.com>

Author: andreiborza

packages/bundler-plugin-core/src/index.ts

@@ -77,8 +77,15 @@ export function sentryUnpluginFactory({
     // Add plugin to emit a telemetry signal when the build starts
     plugins.push({
       name: "sentry-telemetry-plugin",
-      async buildStart() {
-        await sentryBuildPluginManager.telemetry.emitBundlerPluginExecutionSignal();
+      buildStart() {
+        // Technically, for very fast builds we might miss the telemetry signal
+        // but it's okay because telemetry is not critical for us.
+        // We cannot await the flush here because it would block the build start
+        // which in turn would break module federation builds, see
+        // https://github.com/getsentry/sentry-javascript-bundler-plugins/issues/816
+        void sentryBuildPluginManager.telemetry.emitBundlerPluginExecutionSignal().catch(() => {
+          // Nothing for the users to do here. If telemetry fails it's acceptable.
+        });
       },
     });