Re-raise unexpected exceptions instead of swallowing them in tests

[aisk]

When fixing #137420, I found that some existing test code swallows exceptions it doesn't care about.

I think these are simple, test only fixes, so the issue and the news entry aren't required.

[StanFromIreland]

Nice catch! I asked Claude to search for more of these, and it came back with one more:

The one genuine new bug: Lib/test/test_launcher.py:469 (test_search_major_2)

  except subprocess.CalledProcessError:
      if not is_installed("2.7"):
          raise unittest.SkipTest("requires at least one Python 2.x install")
      # ← missing `raise`
  self.assertEqual("PythonCore", data["env.company"])   # data never got assigned

From a glance, it seems correct (although we're unlikely to hit it on most systems), but I think we can include it here.

[aisk]

@StanFromIreland Thank you for the review, updated!

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @StanFromIreland for commit 2c2f096 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F152019%2Fmerge

If you want to schedule another build, you need to add the 🔨 test-with-buildbots label again.

[StanFromIreland]

Looks good, but let's run the Buildbots, just to be safe, since these are all quite platform specific cases.

[miss-islington-app]

Thanks @aisk for the PR, and @StanFromIreland for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14, 3.15.
🐍🍒⛏🤖

[bedevere-app]

GH-152102 is a backport of this pull request to the 3.15 branch.

[bedevere-app]

GH-152103 is a backport of this pull request to the 3.14 branch.

[bedevere-app]

GH-152104 is a backport of this pull request to the 3.13 branch.

[StanFromIreland]

Merged, thanks @aisk.