Add missing perl-datetime-format-strptime

[thespad]

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• [x] I have read the contributing guideline and understand that I have made the correct modifications

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Description:

Closes #228

Benefits of this PR and context:

How Has This Been Tested?

Source / References:

[LinuxServer-CI]

I am a bot, here are the test results for this PR: https://ci-tests.linuxserver.io/lspipepr/tvheadend/18effa8a-pkg-bd124b98-pr-229/index.html https://ci-tests.linuxserver.io/lspipepr/tvheadend/18effa8a-pkg-bd124b98-pr-229/shellcheck-result.xml	Tag	Passed
amd64-18effa8a-pkg-bd124b98-pr-229	✅
arm64v8-18effa8a-pkg-bd124b98-pr-229	✅