chore: remove unused patch files

[szhorvat]

These were patches applied to the C core. They are no longer used. Let's clean out all the old junk.

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[krlmlr]

Thanks!

[szhorvat]

src/config.h.in is also unused. It was part of the old autoconf build system. If we're not going back to autoconf, that should be removed as well (though I still think that sticking with autoconf may be the easiest way forward).