fix(ci/apple): set CMAKE_POLICY_VERSION_MINIMUM=3.5 for the vendored libopus

With cmake now found, Homebrew's CMake 4 refuses the vendored libopus's
`cmake_minimum_required(VERSION <3.5)` ("Compatibility with CMake < 3.5 has been
removed"). Export CMAKE_POLICY_VERSION_MINIMUM=3.5 (the same knob the Windows
build uses) so the cmake crate's child cmake configures the audiopus_sys libopus.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitea/workflows/apple.yml

@@ -46,6 +46,10 @@ jobs:
           BREW_BIN="$(dirname "$BREW")"; export PATH="$BREW_BIN:$PATH"
           command -v cmake >/dev/null || "$BREW" install cmake
           echo "$BREW_BIN" >> "$GITHUB_PATH"
+          # Homebrew's CMake 4 dropped compatibility with the vendored libopus's pre-3.5
+          # `cmake_minimum_required`; treat 3.5 as the policy minimum (the cmake crate's child cmake
+          # inherits this from the env during the xcframework build).
+          echo "CMAKE_POLICY_VERSION_MINIMUM=3.5" >> "$GITHUB_ENV"
 
       - name: Build PunktfunkCore.xcframework
         run: bash scripts/build-xcframework.sh
@@ -97,6 +101,10 @@ jobs:
           BREW_BIN="$(dirname "$BREW")"; export PATH="$BREW_BIN:$PATH"
           command -v cmake >/dev/null || "$BREW" install cmake
           echo "$BREW_BIN" >> "$GITHUB_PATH"
+          # Homebrew's CMake 4 dropped compatibility with the vendored libopus's pre-3.5
+          # `cmake_minimum_required`; treat 3.5 as the policy minimum (the cmake crate's child cmake
+          # inherits this from the env during the xcframework build).
+          echo "CMAKE_POLICY_VERSION_MINIMUM=3.5" >> "$GITHUB_ENV"
 
       - name: Build PunktfunkCore.xcframework (mac + iOS slices)
         run: BUILD_IOS=1 bash scripts/build-xcframework.sh

.gitea/workflows/release.yml

@@ -130,6 +130,10 @@ jobs:
           BREW_BIN="$(dirname "$BREW")"; export PATH="$BREW_BIN:$PATH"
           command -v cmake >/dev/null || "$BREW" install cmake
           echo "$BREW_BIN" >> "$GITHUB_PATH"
+          # Homebrew's CMake 4 dropped compatibility with the vendored libopus's pre-3.5
+          # `cmake_minimum_required`; treat 3.5 as the policy minimum (the cmake crate's child cmake
+          # inherits this from the env during the xcframework build).
+          echo "CMAKE_POLICY_VERSION_MINIMUM=3.5" >> "$GITHUB_ENV"
 
       - name: Build PunktfunkCore.xcframework (mac + iOS + tvOS)
         # tvOS is a tier-3 target (nightly -Zbuild-std): slow on the first build, then cached on