Please remove firefox binaries for ppc64el and s390x from the release pocket

With bug #1962021, the firefox packages in jammy are becoming "transitional packages" that install the firefox snap and wrapper scripts.
However the snap is available only on amd64, armhf and arm64, so to allow the new packages to migrate the existing binaries for ppc64el and s390x that are no longer built from source need to be removed.

For s390x this should be fairly uncontroversial, as Ubuntu desktop in general isn't officially supported on this architecture, and firefox isn't tested there, only known to build successfully (autopkgtests have always been failing there).

For ppc64el this is perhaps a bit more controversial, although the reality is that firefox on this architecture receives no testing from Ubuntu developers (not from the desktop team anyway), and autopkgtests have always been failing there. I don't have numbers of firefox users on this architecture.

Note that upstream is not committed to supporting these architectures either, they fall in their Tier-3 targets (see https://firefox-source-docs.mozilla.org/contributing/build/supported.html#supported-build-targets). Given that the maintenance of the firefox snap is a joint effort between Mozilla and the Ubuntu desktop team, it is unlikely that we will start building the firefox snap for ppc64el or s390x.

The binaries that need removing are: firefox, firefox-dbg, firefox-dev, firefox-geckodriver.

The last three in the list (firefox-dbg, firefox-dev, firefox-geckodriver) do not have any reverse dependencies.
The binary package firefox itself is recommended or suggested by a good number of packages, and is also a direct dependency of the following packages:
  - cinnamon-desktop-environment (all): depends on "firefox-esr | firefox | chromium | gnome-www-browser"
  - firefox-dbg: not an issue as this one also needs removing
  - firefox-geckodriver: not an issue as this one also needs removing
  - firefox-launchpad-plugin (all): depends on "firefox"
  - gnome-core (linux-any): depends on "firefox-esr (>= 78) | firefox (>= 78) | chromium | chromium-browser | epiphany-browser"
  - webhttrack (any): depends on "iceape-browser | iceweasel | icecat | mozilla | firefox | mozilla-firefox | www-browser"
  - x2gothinclient-minidesktop (all): depends on "firefox-esr | firefox | chromium | x-www-browser"