ci: disable many macOS builds we don't use

This disables a bunch of configurations that we don't need to actually 
test for. The main one we want to keep building is Freetype because we
sometimes use this to compare behaviors, but Coretext is the default.

This is one of the primary drivers of CI CPU time.

.github/workflows/test.yml

@@ -24,7 +24,7 @@ jobs:
       - build-linux-libghostty
       - build-nix
       - build-macos
-      - build-macos-matrix
+      - build-macos-freetype
       - build-snap
       - build-windows
       - test
@@ -464,7 +464,7 @@ jobs:
           cd macos
           xcodebuild -target Ghostty-iOS "CODE_SIGNING_ALLOWED=NO"
 
-  build-macos-matrix:
+  build-macos-freetype:
     runs-on: namespace-profile-ghostty-macos-tahoe
     needs: test
     steps:
@@ -493,18 +493,10 @@ jobs:
       - name: Test All
         run: |
           nix develop -c zig build test --system ${{ steps.deps.outputs.deps }} -Drenderer=metal -Dfont-backend=freetype
-          nix develop -c zig build test --system ${{ steps.deps.outputs.deps }} -Drenderer=metal -Dfont-backend=coretext
-          nix develop -c zig build test --system ${{ steps.deps.outputs.deps }} -Drenderer=metal -Dfont-backend=coretext_freetype
-          nix develop -c zig build test --system ${{ steps.deps.outputs.deps }} -Drenderer=metal -Dfont-backend=coretext_harfbuzz
-          nix develop -c zig build test --system ${{ steps.deps.outputs.deps }} -Drenderer=metal -Dfont-backend=coretext_noshape
 
       - name: Build All
         run: |
           nix develop -c zig build --system ${{ steps.deps.outputs.deps }} -Demit-macos-app=false -Drenderer=metal -Dfont-backend=freetype
-          nix develop -c zig build --system ${{ steps.deps.outputs.deps }} -Demit-macos-app=false -Drenderer=metal -Dfont-backend=coretext
-          nix develop -c zig build --system ${{ steps.deps.outputs.deps }} -Demit-macos-app=false -Drenderer=metal -Dfont-backend=coretext_freetype
-          nix develop -c zig build --system ${{ steps.deps.outputs.deps }} -Demit-macos-app=false -Drenderer=metal -Dfont-backend=coretext_harfbuzz
-          nix develop -c zig build --system ${{ steps.deps.outputs.deps }} -Demit-macos-app=false -Drenderer=metal -Dfont-backend=coretext_noshape
 
   build-windows:
     runs-on: windows-2022