github: use fedora:40 image for testing

instead of using ubuntu:jammy and setup-cpp action for prepearing
the building toolchain, use fedora:40 container for building and
testing.

after switching to the github workflow based CI, we've been
seeing test failures due to networking issue:

```
  Failed to install llvm via system package manager Error: Command failed with exit code 35: curl -LJO https://apt.llvm.org/llvm.sh
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed

    0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
    0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
    0     0    0     0    0     0      0      0 --:--:--  0:04:19 --:--:--     0
  curl: (35) OpenSSL SSL_connect: Broken pipe in connection to apt.llvm.org:443
```

since fedora 40 comes with all the dependencies we need, let's
build and test in a container with the fedora:40 image. with,
hopefully the better CDN of the docker, and more reliable mirrors
of fedora repositories, and the package retrievial machinary built
into fedora's package management tools, we should have a more
resilient CI.

please note, in this change, we also

* install git before checkout the repo. the reason is that, unlike
  the github-hosted runner, the fedora:40 image does not have `git`
  installed, so we have to install it manually before using
  "actions/checkout" action.
* install clang-tools-extra when building with C++ modules enabled,
  because cmake and clang depend on clang-scan-deps to analyze the
  dependencies in betweener of C++20 modules.
* use static library in "dev" build mode. this is to work around
  the issue where seastar allocator causes infinite recursive call
  if seastar is compiled as a shared library. this only happens when
  the tree is compiled with newer glibc. see also #2247

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

.github/workflows/test.yaml

@@ -7,7 +7,6 @@ on:
   workflow_call:
     inputs:
       compiler:
-        # only the compilers supported by setup-cpp can be used
         description: 'the C++ compiler to use'
         type: string
         required: true
@@ -33,7 +32,12 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
+    container: fedora:40
     steps:
+      - name: Install Git
+        run: |
+          sudo dnf -y install git
+
       - uses: actions/checkout@v4
         with:
           submodules: "${{ contains(inputs.enables, 'dpdk') }}"
@@ -42,31 +46,40 @@ jobs:
         run: |
           sudo ./install-dependencies.sh
 
-      - name: Install ${{ inputs.compiler }}
-        uses: aminya/setup-cpp@master
-        with:
-          compiler: ${{ inputs.compiler }}
-          ccache: true
-          # ubuntu:latest comes with CMake 3.29, so we just need to install
-          # ninja. see
-          # https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2204-Readme.md#tools
-          ninja: "${{ contains(inputs.enables, 'cxx-modules') }}"
+      - name: Install clang++
+        if: ${{ inputs.compiler == 'clang++' }}
+        run: |
+          sudo dnf -y install clang
+
+      - name: Install clang-scan-deps
+        if: ${{ contains(inputs.enables, 'cxx-modules') }}
+        run: |
+          sudo dnf -y install clang-tools-extra
+
+      - name: Install ccache
+        run: |
+          sudo dnf -y install ccache
 
       - name: Setup ccache
         uses: hendrikmuhs/ccache-action@v1
         with:
           key: ${{ inputs.compiler }}-${{ inputs.standard }}-${{ inputs.mode }}-${{ inputs.enables }}
 
       - name: Configure
-        run: >
-          ./configure.py
-          --ccache
-          --c++-standard ${{ inputs.standard }}
-          --compiler $CXX
-          --c-compiler $CC
-          --mode ${{ inputs.mode }}
-          ${{ inputs.options }}
-          ${{ inputs.enables }} ;
+        run: |
+          if [ ${{ inputs.compiler }} = "clang++" ]; then
+            CC=clang
+          else
+            CC=gcc
+          fi
+          ./configure.py                          \
+            --ccache                              \
+            --c++-standard ${{ inputs.standard }} \
+            --compiler ${{ inputs.compiler }}     \
+            --c-compiler $CC                      \
+            --mode ${{ inputs.mode }}             \
+            ${{ inputs.options }}                 \
+            ${{ inputs.enables }}
 
       - name: Build
         run: cmake --build build/${{inputs.mode}}

.github/workflows/tests.yaml

@@ -16,8 +16,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # only the compilers supported by setup-cpp
-        compiler: [clang++-18, gcc-13]
+        compiler: [clang++, g++]
         standard: [20, 23]
         mode: [dev, debug, release]
     with:
@@ -32,7 +31,7 @@ jobs:
     strategy:
       fail-fast: false
     with:
-      compiler: clang++-18
+      compiler: clang++
       standard: 23
       mode: release
       enables: --enable-dpdk
@@ -43,7 +42,7 @@ jobs:
     strategy:
       fail-fast: false
     with:
-      compiler: clang++-18
+      compiler: clang++
       standard: 23
       mode: debug
       enables: --enable-cxx-modules