ci: repair the gersemi format check

Homebrew no longer runs formula install steps from untrusted third party taps, so the gersemi check fails while installing the formatter:

  Skipping obsproject/tools because it is not trusted.
  Error: unknown install step: run

Refresh the Homebrew metadata and trust the obsproject/tools tap explicitly before installing, mirroring the fix applied upstream in obs-studio.

Signed-off-by: EdueskaWeiz <48769486+EdueskaWeiz@users.noreply.github.com>

Author: EdueskaWeiz

.github/actions/run-gersemi/action.yaml

@@ -35,6 +35,7 @@ runs:
         echo ::group::Install Dependencies
         eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"
         echo "/home/linuxbrew/.linuxbrew/bin:/home/linuxbrew/.linuxbrew/sbin" >> $GITHUB_PATH
+        brew update
         brew install --quiet zsh
         echo ::endgroup::
 
@@ -50,6 +51,8 @@ runs:
         if (( ${+RUNNER_DEBUG} )) setopt XTRACE
 
         print ::group::Install gersemi
+        brew update
+        brew trust obsproject/tools
         brew install --quiet obsproject/tools/gersemi
         print ::endgroup::