ci: Switch to version 4 of GitHub artifact actions (#31357)

* ci: Switch to version 4 of GitHub artifact actions

This switches to version 4 of the GitHub artifact actions, which
requires producing a single artifact per job and adding merge steps. In
addition, the names of artifacts are standardized:

- Build: <profile>-binary-<platform>
- Full WPT results (only on failure): wpt-full-logs-<platform>-<layout>
- Filtered WPT results (only on failure): wpt-filtered-logs-<platform>-<layout>

* Delete merged build timings and combine with Result job

* Always archives logs even after test failures

* Correct the name of the log files for WPT import

.github/workflows/main.yml

@@ -57,9 +57,15 @@ jobs:
       - "build-linux"
       - "build-android"
     steps:
-      - name: Mark the job as successful
+      - name: Merge build timings
+        uses: actions/upload-artifact/merge@v4
+        with:
+          name: cargo-timings
+          pattern: cargo-timings-*
+          delete-merged: true
+      - name: Success
         if: ${{ !contains(needs.*.result, 'failure') && !contains(needs.*.result, 'cancelled') }}
         run: exit 0
-      - name: Mark the job as unsuccessful
+      - name: Failure
         if: contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled')
         run: exit 1