ci: do not check/upload `packages-dist/` UMD bundle sizes multiple times (#33987)

At the end of the `integration/run_tests.sh` script, we check and upload
the payload sizes of UMD bundles in `dist/packages-dist/`. At some
point, we started sharding the integration tests on CI to speed the
overall build time. As a result, checking and uploading of UMD bundle
sizes was run multiple times (once per shard).

Given that the data is identical on each shard, the data was just
overwriting the previously uploaded data. Even if the end result is the
same, checking and uploading the data multiple times is wasteful.

This commit fixes `integration/run_tests.sh` to only check/upload UMD
bundle sizes on the 1st shard.

PR Close #33987

integration/run_tests.sh

@@ -72,6 +72,6 @@ for testDir in ${TEST_DIRS}; do
   )
 done
 
-if $CI; then
+if $CI && [[ "$SHARD_INDEX" == "0" ]]; then
   trackPayloadSize "umd" "../dist/packages-dist/*/bundles/*.umd.min.js" false
 fi