community/bitcoin: upgrade to 25.0
Upgrade community/bitcoin to the latest available release. See https://github.com/bitcoin/bitcoin/releases/tag/v25.0 & https://bitcoincore.org/en/2023/05/26/release-25.0/.
Drop the GCC 13 patch as it's no-longer required. Rebase the others.
Remove no-longer a configure option --disable-openssl-tests
.
Remove #gen=1 from bitcoin.conf, as that is also no-longer an option.