Don't report test results for closed PRs

[mrobinson]

When doing a try run, bors will often push the last closed merge onto the branch before pushing the change to try. This means that test results get reported on closed PRs. There are two issues with this:

1. Doing too much work on the bots.
2. Extra results on closed PRs.

This changes fixes the second issue.

Fixes #29583.

---

• ./mach build -d does not report any errors
• ./mach test-tidy does not report any errors
• These changes fix Test results are reported for pull requests multiple times after it has merged #29583

• These changes do not require tests because they fix a infrastructure issue.

[mukilan]

@bors-servo r+

[bors-servo]

📌 Commit faa0769 has been approved by mukilan

[bors-servo]

⌛ Testing commit faa0769 with merge 0e1d1e3...

[github-actions]

Test results for linux-wpt-layout-2013 from try job (#4892625992):

Flaky unexpected result (9)

• TIMEOUT [expected OK] /_webgl/conformance/glsl/misc/shader-uniform-packing-restrictions.html (#28103)
  • NOTRUN [expected PASS] subtest: Overall test
• TIMEOUT [expected OK] /_webgl/conformance/glsl/misc/shader-with-non-reserved-words.html (#16216)
  • NOTRUN [expected PASS] subtest: Overall test
• TIMEOUT [expected OK] /_webgl/conformance/uniforms/out-of-bounds-uniform-array-access.html (#26225)
  • NOTRUN [expected PASS] subtest: Overall test
• TIMEOUT [expected OK] /html/browsers/browsing-the-web/navigating-across-documents/failure-check-sequence.https.html (#28207)
  • TIMEOUT [expected FAIL] subtest: COEP check precedes X-Frame-Options check Test timed out
• TIMEOUT [expected OK] /html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/form-requestsubmit.html (#28716)
  • TIMEOUT [expected FAIL] subtest: Replace before load, triggered by formElement.requestSubmit() Test timed out
• TIMEOUT [expected FAIL] /html/canvas/element/manual/drawing-text-to-the-canvas/canvas.2d.disconnected.html (#29224)
• TIMEOUT [expected OK] /html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-2.html (#22667)
  • TIMEOUT [expected FAIL] subtest: Check that popups from a sandboxed iframe escape the sandbox if
    allow-popups-to-escape-sandbox is used Test timed out
• ERROR [expected OK] /html/semantics/scripting-1/the-script-element/defer-script/async-script.html?reload (#29054)
• TIMEOUT [expected OK] /webmessaging/without-ports/017.html (#24486)
  • TIMEOUT [expected PASS] subtest: origin of the script that invoked the method, about:blank Test timed out

Stable unexpected results that are known to be intermittent (7)

• FAIL [expected PASS] /css/css-text/white-space/trailing-other-space-separators-break-spaces-011.html (#25875)
• OK [expected TIMEOUT] /fetch/local-network-access/iframe.tentative.https.window.html (#29605)
  • FAIL [expected TIMEOUT] subtest: public to local, grandparent navigates: success. timeout adding grandchild
• OK /html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-iframe-contentWindow.html (#28681)
  • FAIL [expected PASS] subtest: load & pageshow events do not fire on contentWindow of <iframe> element created with src='' assert_unreached: load should not be fired Reached unreachable code
• OK /html/browsers/browsing-the-web/navigating-across-documents/javascript-url-security-check-same-origin-domain.sub.html (#29122)
  • PASS [expected FAIL] subtest: javascript: URL security check for same-origin-domain but not same-origin
• OK [expected TIMEOUT] /html/browsers/history/the-history-interface/traverse-during-unload.html (#28688)
  • PASS [expected TIMEOUT] subtest: Traversing the history during unload
• OK /html/syntax/parsing/DOMContentLoaded-defer.html (#21550)
  • FAIL [expected PASS] subtest: The end: DOMContentLoaded and defer scripts assert_false: DOMContentLoaded should not have fired before executing a task queued from a defer script expected false got true
• OK /html/webappapis/dynamic-markup-insertion/document-write/module-tla-delayed.html (#29137)
  • PASS [expected FAIL] subtest: document.write in an imported module

[bors-servo]

☀️ Test successful - checks-github
Approved by: mukilan
Pushing 0e1d1e3 to master...