bpo-42257: handle empty string in variable executable in platform.libc_ver()

[kurochan]

https://bugs.python.org/issue42257

[the-knights-who-say-ni]

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[github-actions]

This PR is stale because it has been open for 30 days with no activity. Remove stale label or comment or this will be closed in 5 days

[kurochan]

Can anyone review this PR? 🤔

[malemburg]

The patch looks good. Could you please also add a NEWS entry ?

[malemburg]

The nntplib test fails, preventing a merge. This doesn't seem to be related to this PR, so I guess we'll have to wait and then rebase the PR after this is fixed in the master branch.

[malemburg]

@kurochan Could you please rebase the PR. The nntplib issue (#24037) should be resolved now.

[bedevere-bot]

@malemburg: Please replace # with GH- in the commit message next time. Thanks!

[malemburg]

Thanks for the patch @kurochan.