Unfortunately, last I checked, shellcheck is not compatible with M1 macs yet. I love the tool so much that I while I wait for compatibility, I manually check my shell scripts at the web UI.
Yeah, there are still issues with Haskell and the new Mac architecture. Pandoc and ShellCheck are two of the essential tools affected. In the case of ShellCheck, I just downloaded an x86 binary from the GitHub Releases page and put it in /usr/local/bin. Good enough for the time being.
https://github.com/koalaman/shellcheck/releases