ci(test): use ARM ubuntu linux for more CI jobs #34908

Problem:
We temporarily disabled linux arm ci because of stability issues with
the runner. #32339 Since then, the hardware was changed, so we can try
re-enabling ARM linux CI. https://github.com/actions/partner-runner-images/issues/47#issuecomment-2678170225

Solution:
- re-enable arm linux ci. reverts 8e4b77134a
- also use arm image for these jobs, where arm seems to run much faster:
- `lint` (step: `clang-tidy`)
    - master: 1m5s
    - this pr (linux ARM): 37s
- `clang-analyzer` (step: `cmake --build ...`)
    - master: 10m
    - this pr (linux ARM) 5m 55s
- `with-external-deps` (step: `Build`)
    - master: 26s
    - this pr (linux ARM): 21s

.github/workflows/notes.md

@@ -54,7 +54,7 @@ If your system does not have the required glibc version, try the (unsupported) [
 2. Extract: `tar xzvf nvim-linux-x86_64.tar.gz`
 3. Run `./nvim-linux-x86_64/bin/nvim`
 
-### Linux (arm64) - Untested
+### Linux (arm64)
 
 #### AppImage
 

.github/workflows/test.yml

@@ -28,7 +28,7 @@ env:
 
 jobs:
   lint:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-24.04-arm
     timeout-minutes: 10
     env:
       CC: clang
@@ -38,7 +38,7 @@ jobs:
 
       - name: Install stylua
         run: |
-          wget --directory-prefix="$BIN_DIR" https://github.com/JohnnyMorganz/StyLua/releases/latest/download/stylua-linux-x86_64.zip
+          wget --directory-prefix="$BIN_DIR" https://github.com/JohnnyMorganz/StyLua/releases/latest/download/stylua-linux-aarch64.zip
           (cd "$BIN_DIR"; unzip stylua*.zip)
 
       - name: Build third-party deps
@@ -82,7 +82,7 @@ jobs:
         run: cmake --build build --target lintc-uncrustify
 
   clang-analyzer:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-24.04-arm
     timeout-minutes: 20
     env:
       CC: clang
@@ -111,7 +111,7 @@ jobs:
             { runner: ubuntu-24.04, os: ubuntu, flavor: asan, cc: clang, flags: -D ENABLE_ASAN_UBSAN=ON },
             { runner: ubuntu-24.04, os: ubuntu, flavor: tsan, cc: clang, flags: -D ENABLE_TSAN=ON },
             { runner: ubuntu-24.04, os: ubuntu, flavor: release, cc: gcc, flags: -D CMAKE_BUILD_TYPE=Release -D ENABLE_TRANSLATIONS=ON },
-            # { runner: ubuntu-24.04-arm, os: ubuntu, flavor: arm, cc: gcc, flags: -D CMAKE_BUILD_TYPE=RelWithDebInfo },
+            { runner: ubuntu-24.04-arm, os: ubuntu, flavor: arm, cc: clang, flags: -D CMAKE_BUILD_TYPE=RelWithDebInfo },
             { runner: macos-13, os: macos, flavor: intel, cc: clang, flags: -D CMAKE_FIND_FRAMEWORK=NEVER, deps_flags: -D CMAKE_FIND_FRAMEWORK=NEVER },
             { runner: macos-15, os: macos, flavor: arm, cc: clang, flags: -D CMAKE_FIND_FRAMEWORK=NEVER, deps_flags: -D CMAKE_FIND_FRAMEWORK=NEVER },
             { runner: ubuntu-24.04, os: ubuntu, flavor: puc-lua, cc: gcc, deps_flags: -D USE_BUNDLED_LUAJIT=OFF -D USE_BUNDLED_LUA=ON, flags: -D PREFER_LUA=ON },
@@ -124,6 +124,10 @@ jobs:
             build: { flavor: puc-lua }
           - test: oldtest
             build: { flavor: tsan }
+          - test: unittest
+            build: { runner: ubuntu-24.04-arm }
+          - test: oldtest
+            build: { runner: ubuntu-24.04-arm }
     runs-on: ${{ matrix.build.runner }}
     timeout-minutes: 45
     env:
@@ -220,7 +224,7 @@ jobs:
     uses: ./.github/workflows/test_windows.yml
 
   with-external-deps:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-24.04-arm
     timeout-minutes: 10
     env:
       CC: gcc