Version 4.9 compatibility breaks #10989

We have been postponing some changes due to them being user-visible compatibility breaks, which should go into a "major" version (e.g. 4.9).

Likely not everything will go into 4.9 though, realistically we might have to skip stuff.

• bump min required python version (to 3.11?)
  • atm android bundles 3.11
• bump min macos version
  • so we can bump bundled Qt
  • also means build machine needs to be upgraded
    • should prob look at ARM support (Native Apple Silicon Support (m1, arm, macOS, osx) #7557) at the same time
• bump appimage docker base image (deb 11 is deprecated)
  • bump to 12
  • ref appimage: debian 11 LTS is EOL, we should bump to debian 12 #10950
• android bump minSdkVersion from "8.0" to "9.0"
  • needed for QtMultimedia-based QR scanner (qr scanning: rm zbar, rm barcodescannerview, use zxing-cpp #10955)
• start auto-closing static_remotekey chans
  • so that at some point in the future, we can strip out old code
    • though how exactly the future code removal would look like is still TBD as Android users cannot downgrade,
      and there might be users who skip any number of intermediate apk versions when upgrading...
• electrum protocol 1.7
  • ref Protocol 1.7 #10627
  • current plan is to require 1.7 as the min protocol version
• animated QR codes?? compat break with current format
  • prob BC-UR 2.0, not bbqr
  • ref Support UR2.0 QR codes (for PSBTs) #7905
  • compromise (maintainability vs UX):
    • add config option: "show BC-UR animated QR codes for PSBTs", default on, shown in the Preferences of the GUIs
    • new code support decoding of both old QR codes and new QR codes
    • new code by default encodes PSBT QR codes using new format, unless the user toggles the config option
    • some versions later in the future, we remove support of the old base43-based format completely

More ambitious:

• deprecate non-deterministic lightning??
  • ref Deprecate wallets with non-deterministic lightning keys?? #10995