messages.pot header not being updated

### Problem

The `POT-Creation-Date` in the `messages.pot` file hasn't been updated in the last two years, even though a number of changes have been made to it. This makes it difficult to tell how out of date a given language's `messages.po` file is and how urgently it should be updated.

https://github.com/internetarchive/openlibrary/blob/4f4def6691ac3fda9b747f1775613812f5b1d53b/openlibrary/i18n/messages.pot#L12

~The `Generated-By` line is also wrong since I believe it is now generated by some homebrew script rather than a standard tool like Babel.~ As pointed out by Copilot, although a homebrew script is used as the driver, the extraction & `.pot` writing is done by the PyBabel library routines.

https://github.com/internetarchive/openlibrary/blob/4f4def6691ac3fda9b747f1775613812f5b1d53b/openlibrary/i18n/messages.pot#L19

https://github.com/internetarchive/openlibrary/blame/4f4def6691ac3fda9b747f1775613812f5b1d53b/openlibrary/i18n/messages.pot

### Reproducing the bug

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### Breakdown

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