Brew by default doesn't install unsupported software versions. Like at this time, php7.3 was no longer supported.
Installing it disables it and install instead the latest version (8.1.3 at this time).
1~$ brew install firstname.lastname@example.org 2Running `brew update --preinstall`... 3==> Auto-updated Homebrew! 4Updated 2 taps …
1brew cask install powershell Run
1pwsh To update/upgrade later on:
1brew update 2brew cask upgrade powershell See https://docs.microsoft.com/en-us/powershell/scripting/install/installing-powershell-core-on-macos?view=powershell-7