Allow forcing bottle installation.
brew-reinstall: don't try and rebuild bottles.
brew-reinstall: don't list --force in args.
brew-postinstall: add new command.

Runs post-install jobs in case they failed or need rerun for any reason.
formula_installer: handle post_install exceptions.

Warn users and point them to `brew postinstall` (which can provide a
backtrace).

Closes #21887.
fontconfig: remove patch that was upstreamed ages ago
fontconfig 2.10.95
pango: update deps

 - Always depend on newer fontconfig
 - Remove outdated comment about cairo; we always use our cairo these
   days anyway
harfbuzz: does *not* depend on fontconfig
harfbuzz: depends on freetype
harfbuzz 0.9.20
harfbuzz: ensure icu is enabled