Reason for 1.9.3 release tarball change?

Hi!

I help out with the Homebrew project (https://brew.sh) on occasion, and 
it's come to our attention that the doxygen-1.9.3.tar.gz release tarball 
on your website was changed sometime after its initial release. As our 
doxygen formula tracks SHA256 checksums of source tarballs, we were 
alerted to this after one of our users tried to build from source and 
got a checksum error: 
https://github.com/Homebrew/discussions/discussions/2726

I downloaded the current tarball to verify it myself, and noticed a 
number of files in the src directory dated after the Dec 31 initial 
release. Since there's no accompanying note about the changes, may I ask 
what they were? That would help determine whether we have to rebuild and 
release new precompiled bottles for all our users.

Thanks much!

Best Regards,
Adrian