Update macos container's version and upgrade macos's grpc (#2568)

The macos-13 image was dropped in actions/runner-images#13046, so we have to upgrade to macos-14.

Older gRPC versions don't support macos-14 well so we have to use a newer version (on mac only for now).

Fixes https://github.com/clangd/clangd/issues/2562

.github/workflows/autobuild.yaml

@@ -158,11 +158,12 @@ jobs:
             "-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded"
             "-DLLVM_ENABLE_PDB=ON"
             "-DLLVM_PARALLEL_LINK_JOBS=1"
+          grpc_version: v1.36.3
           grpc_cmake: >-
             "-DgRPC_MSVC_STATIC_RUNTIME=ON"
           binary_extension: ".exe"
         - name: mac
-          os: macos-13
+          os: macos-14
           preinstall: brew install ninja zlib p7zip
           cflags: -O3 -gline-tables-only -DNDEBUG
           cmake: >-
@@ -172,6 +173,8 @@ jobs:
             "-DCMAKE_OSX_ARCHITECTURES=x86_64;arm64"
             "-DCMAKE_OSX_DEPLOYMENT_TARGET=10.13"
             "-DCMAKE_POLICY_VERSION_MINIMUM=3.5"
+            "-Dabsl_DIR=$HOME/grpc-installation/lib/cmake/absl"
+          grpc_version: v1.51.3
           # BoringSSL doesn't support universal binaries when building with ASM.
           grpc_cmake: >-
             "-DOPENSSL_NO_ASM=ON"
@@ -195,6 +198,7 @@ jobs:
             "-DLLVM_STATIC_LINK_CXX_STDLIB=ON"
             "-DLLVM_ENABLE_ZLIB=FORCE_ON"
             "-DCMAKE_PROJECT_INCLUDE=$GITHUB_WORKSPACE/.github/workflows/linux-static-deps.cmake"
+          grpc_version: v1.36.3
           # Using c-ares as a module prevents dynamic linking of unneeded
           # libraries. All other gRPC dependencies can be built from sources.
           grpc_cmake: >-
@@ -228,7 +232,7 @@ jobs:
         # We use the same version of gRPC for LLVM's clangd-ubuntu-tsan
         # buildbot.
         # https://github.com/llvm/llvm-zorg/blob/main/buildbot/google/docker/buildbot-clangd-ubuntu-clang/Dockerfile
-        ref: v1.36.3
+        ref: ${{ matrix.config.grpc_version }} 
         submodules: recursive
     - name: Build gRPC
       run: >