"try-job" parsing logic seems to be space-sensitive

[RalfJung]

I don't know exactly what I did, but I got this error when trying to trigger a try build:

INFO:root:Job type: TryRunType(custom_jobs=[' aarch64-apple'])
Traceback (most recent call last):
  File "/home/runner/work/rust/rust/src/ci/github-actions/ci.py", line 314, in <module>
    calculate_job_matrix(data)
  File "/home/runner/work/rust/rust/src/ci/github-actions/ci.py", line 266, in calculate_job_matrix
    jobs = calculate_jobs(run_type, job_data)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/rust/rust/src/ci/github-actions/ci.py", line 153, in calculate_jobs
    raise Exception(
Exception: Custom job(s) `[' aarch64-apple']` not found in auto jobs

Might be worth stripping leading and trailing spaces?

Cc @rust-lang/infra

[kennytm]

rust/src/ci/github-actions/ci.py

Lines 96 to 100 in 6dfeab5

	regex = re.compile(r"^try-job: (.*)", re.MULTILINE)
	jobs = []
	for match in regex.finditer(ctx.commit_message):
	jobs.append(match.group(1))
	return jobs

perhaps change the regex to ^try-job:[ \t]*(.*) (or just search for \ntry-job, don't use a regex)

[Kobzol]

Heh, I was just thinking about this when implementing #136864, but it seems I still missed one trim there. I will fix it once that PR gets merged.