meta: add flaky test issue template

Add a flaky test issue template to ensure that enough information is provided for investigation

Author: Ash Cripps

.github/ISSUE_TEMPLATE/4-report-a-flaky-test.md

@@ -0,0 +1,30 @@
+---
+name: Report a flaky test
+about: Report a flaky test in our CI
+labels: "CI / flaky test"
+
+---
+
+<!--
+Thank you for reporting a flaky test.
+
+Flaky tests are tests that fail occaisonally in Node.js CI, but not consistently enough to block PRs from landing, 
+or that are failing in CI jobs or test modes that are not run for every PR. 
+
+Please fill in as much of the template below as you're able.
+
+Test: The test that is flaky - e.g. `test-fs-stat-bigint`
+Platform: The platform the test is flaky on - e.g. `macos` or `linux`
+Console Output: A pasted console output from a failed CI job showing the whole failure of the test
+Build Links: Links to builds affected by the flaky test
+
+If any investigation has been done, please include any information found, such as how consistently the test fails, whether the failure could be reproduced locally, when the test started failing, or anything else you think is relevant.
+-->
+
+* **Test**:
+* **Platform**:
+* **Console Output:**
+```
+REPLACE ME
+```
+* **Build Links**: