ci: set xcode sdk version when building dylib (#16466)

The Coder Desktop app might not be able to load the dylib because the
hardened runtime version is different. Right now, without manually
selecting an XCode version, the dylib is built with hardened runtime
version `14.5`. The macOS app is built with XCode 16 SDK, which uses
version `15.0`.

Even if this isn't an issue, I think it's preferable to select a
specific xcode version here to avoid things breaking from under us.

.github/workflows/ci.yaml

@@ -940,11 +940,7 @@ jobs:
     if: needs.changes.outputs.go == 'true' || needs.changes.outputs.ci == 'true' || github.ref == 'refs/heads/main'
     runs-on: ${{ github.repository_owner == 'coder' && 'depot-macos-latest' || 'macos-latest' }}
     steps:
-      - name: Harden Runner
-        uses: step-security/harden-runner@cb605e52c26070c328afc4562f0b4ada7618a84e # v2.10.4
-        with:
-          egress-policy: audit
-
+      # Harden Runner doesn't work on macOS
       - name: Checkout
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
@@ -957,6 +953,11 @@ jobs:
           echo "$(brew --prefix gnu-getopt)/bin" >> $GITHUB_PATH
           echo "$(brew --prefix make)/libexec/gnubin" >> $GITHUB_PATH
 
+      - name: Switch XCode Version
+        uses: maxim-lobanov/setup-xcode@60606e260d2fc5762a71e64e74b2174e8ea3c8bd # v1.6.0
+        with:
+          xcode-version: "16.0.0"
+
       - name: Setup Go
         uses: ./.github/actions/setup-go
 

.github/workflows/release.yaml

@@ -36,11 +36,7 @@ jobs:
   build-dylib:
     runs-on: ${{ github.repository_owner == 'coder' && 'depot-macos-latest' || 'macos-latest' }}
     steps:
-      - name: Harden Runner
-        uses: step-security/harden-runner@cb605e52c26070c328afc4562f0b4ada7618a84e # v2.10.4
-        with:
-          egress-policy: audit
-
+      # Harden Runner doesn't work on macOS.
       - name: Checkout
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
@@ -61,6 +57,11 @@ jobs:
           echo "$(brew --prefix gnu-getopt)/bin" >> $GITHUB_PATH
           echo "$(brew --prefix make)/libexec/gnubin" >> $GITHUB_PATH
 
+      - name: Switch XCode Version
+        uses: maxim-lobanov/setup-xcode@60606e260d2fc5762a71e64e74b2174e8ea3c8bd # v1.6.0
+        with:
+          xcode-version: "16.0.0"
+
       - name: Setup Go
         uses: ./.github/actions/setup-go