Add AddressSanitizer

Do not override the compilers (the CC and CXX environment variables).
For some reason, using CC=clang and CXX=clang++ (Clang 14.0.0) with
AddressSanitixer results in segmentation faults in the ubuntu-latest os
image.

.github/workflows/ci-unix-static-sanitized.yml

@@ -11,15 +11,16 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
-        sanitizer: [ undefined ] # TODO(yguyon): Add address, memory, thread
-
-    env:
-      CC: clang
-      CXX: clang++
+        sanitizer: [ address, undefined ] # TODO(yguyon): Add memory, thread
 
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
+      - name: Set up Clang (on Linux)
+        if: runner.os == 'Linux'
+        uses: egor-tensin/setup-clang@v1
+        with:
+          version: 14
       - name: Setup cmake
         uses: jwlawson/actions-setup-cmake@959f1116cf9f1ae42fff8ec1a4aaae6d4a0e348b # v2.0.1
         with:
@@ -31,13 +32,6 @@ jobs:
       - uses: seanmiddleditch/gha-setup-ninja@8b297075da4cd2a5f1fd21fe011b499edf06e9d2 # v4
       - run: pip install meson
 
-      - name: Cache external dependencies
-        id: cache-ext
-        uses: actions/cache@ab5e6d0c87105b4c9c2047343972218f562e4319 # v4.0.1
-        with:
-          path: ext
-          key: ${{ runner.os }}-${{ matrix.sanitizer }}-${{ hashFiles('ext/*.cmd') }}
-
       - name: Build aom
         if: steps.cache-ext.outputs.cache-hit != 'true'
         working-directory: ./ext
@@ -91,5 +85,6 @@ jobs:
         run: ninja
       - name: Run AVIF Tests
         working-directory: ./build
-        # ASAN_OPTIONS=allocator_may_return_null=1 may be necessary for address sanitizer.
         run: ctest -j $(getconf _NPROCESSORS_ONLN) --output-on-failure
+        env:
+          ASAN_OPTIONS: allocator_may_return_null=1