Bump python-bitcointx to v1.1.1.post0

[kristapsk]

Should fix PSBT related incompatibilities with some wallets in BIP78 payjoin receiver.

Related - spesmilo/electrum#6257 and WalletWasabi/WalletWasabi#4427.

[AdamISZ]

ACK (but needs baseline test that JM-JM BIP78 is still working, if someone else does that before me feel free to merge).

[AdamISZ]

OK I found some spare time, test suite passes - which includes explicit psbt tests and tests of functionality including psbt, and also, didn't take much effort to test that JM sender and receiver of BIP78 is still working fine, albeit that is a trivial sanity test, the more substantial one is checking for Wasabi sender-side compatibility, but I believe that has been done, so merging. (note: to test this i just did pip install --update, just pulling the branch would not of course have been helpful).

[kristapsk]

more substantial one is checking for Wasabi sender-side compatibility, but I believe that has been done

Don't trust, verify! :) I haven't yet tested that one, just did some testing that this does not break anything else before creating this PR (also, it's >=, so this should not have any actual effect on a new installs anyway).