Update ARM script to use GHC 9.2.4

[laurenceisla]

Description of issue

As mentioned in #2671 (comment), we won't use GHC 8.10.7 anymore, so the ARM build script should reflect that. The way the GHC version is detected should be changed, maybe doing ghcup set ghc <ghc_version> and if it fails install it. These are the relevant lines:

postgrest/.github/scripts/arm/build.sh

Lines 33 to 45 in 2a28890

	install_ghc() {
	ghcup install ghc 8.10.7
	ghcup set ghc 8.10.7
	}
	install_packages
	# Add ghcup to the PATH for this session
	[ -f ~/.ghcup/env ] && source ~/.ghcup/env
	ghcup --version || install_ghcup
	cabal --version || install_cabal
	ghc --version || install_ghc