doc,meta: add issue template for flaky tests

[refack]

New template for reporting flaky tests. Lists the data point relevant to later investigate the issue (i.e. CI-job, CI-worker, link to test code, console output).
Examples:
#24449
#24403
#24397

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[nodejs-github-bot]

@refack sadly an error occured when I tried to trigger a build :(

[refack]

Anyone know how I can test this? NM
See https://github.com/refack/node/issues/new/choose

[refack]

BTW: this is also an option, with the long URIs out of line (👍 / 👎 your opinion)

<!--
Thank you for reporting a possible flaky test in Node.js.

Please fill in as much of the template below as you can.

-->
* test file - [NAME_OF_TEST_WITH_SUITE (e.g. parallel/test-https)][1]
* ci job  - [CI_JOB_DESCRIPTOR (e.g. aix/21613)][2]
* ci worker - [CI_WORKER_NAME](https://ci.nodejs.org/computer/CI_WORKER_NAME/)
* output:
  ``
  CI console output for the failing test.
  Or content of JUnit test details page.
  Note: should be indented with 2 spaces to align with * bullet point.
  ``

[1]: https://github.com/nodejs/node/blob/master/test/NAME_OF_TEST_WITH_SUITE.js
[2]: https://ci.nodejs.org/job/node-test-CI_JOB_DESCRIPTOR

[targos]

/cc @Trott who opens most of those issues

[Trott]

/cc @Trott who opens most of those issues

I'm -0 on this.

• I'd personally find a template to be an obstacle. I currently delete everything from the template and start entering the data.

• I think templates should be outward facing. Adding a template for something that external folks aren't going to understand or have access to fill out will put one more choice in their path. I'd prefer they have fewer and clearer choices.

• While it's nice to get all the info in this template, a lot of people won't know how to get some of it, and I wouldn't want that to discourage them from reporting.

Still, just a -0, not blocking or anything. If you put it in, I'll try to use it. If it causes significant problems (unlikely), we can remove it. If it helps, great.

[Trott]

The name/description might make people think that it's about unreliable tests they experience on their local machines (and maybe that still qualifies?) but the information requested seems to assume CI. Maybe that's OK, but maybe it's not, so I'm just pointing it out....

[Trott]

I'd remove this. Having to indent output by two spaces can be annoying/tedious. It's OK if it's not indented (or does that cause a big problem--seems mostly aesthetics)?

[refack]

The name/description might make people think that it's about unreliable tests they experience on their local machines (and maybe that still qualifies?)

Yeah, that might be a good thing.

I'd personally find a template to be an obstacle. I currently delete everything from the template and start entering the data.

I'm wired to like structure, but if we don't have consensus ¯_(ツ)_/¯
Since I'm probably the second most frequent opener of these, I can keep mine consistent.