chore: reproduce problem with external getting instrumented

Author: alexeagle

.github/workflows/ci.yaml

@@ -66,7 +66,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - run: ./minimal_download_test.sh
-      - run: bazel coverage //src/...
+      - run: bazel coverage //...
       - uses: hrishikesh-kadam/setup-lcov@6c1aa0cc9e1c02f9f58f01ac599f1064ccc83470 # v1
       # The github-actions-report-lcov doesn't follow symlinks, so get an absolute path
       - run: echo "bazel_testlogs=$(bazel info bazel-testlogs)" >> $GITHUB_ENV

e2e/use_release/.bazelrc

@@ -1,3 +1,3 @@
-# Don't instrument the root folder, since that walks into the //external folder too
+# Don't instrument the //external folder
 # See https://bazelbuild.slack.com/archives/C07HTMQFTBN/p1737600241213179?thread_ts=1736875351.548719&cid=C07HTMQFTBN
-coverage --instrumentation_filter=//src
+coverage --instrumentation_filter=-//external