* CI: upgrade runner to Ubuntu 22.04
- Compile with GCC 11 and Clang 14.
- Remove redundant PPAs.
- Use system provided Meson.
- Update LeakSanitizer suppressions.
* CI: ensure `VIPS_BLOCK_UNTRUSTED` is tested
`magicksave` cannot be used for testing when building with
`-Dmodules=enabled` (default), since that would require the
loadable modules to be installed first.
468c13693b