Clarify Windows ARM clang job naming

Rename the Windows ARM clang jobs to windows_arm_clang_msvc and windows_arm_clang_msys2 and adjust their display names to clang-msvc / clang-msys2. The first runs clang against the MSVC/Windows SDK toolchain and python.org CPython for Windows ARM, while the second runs clang inside the MSYS2/MinGW-w64 CLANGARM64 environment with MSYS2 Python.

Using clearly distinguished job names makes it easier to discuss failures and behavior in each environment without ambiguity, both in logs and in PR review discussions.

Author: rwgk

.github/workflows/ci.yml

@@ -1206,7 +1206,8 @@ jobs:
       - name: Clean directory
         run: git clean -fdx
 
-  windows_arm:
+  # Clang with MSVC/Windows SDK toolchain + python.org CPython (Windows ARM)
+  windows_arm_clang_msvc:
     if: github.event.pull_request.draft == false
 
     strategy:
@@ -1218,7 +1219,7 @@ jobs:
     runs-on: "${{ matrix.os }}"
     timeout-minutes: 90
 
-    name: "🐍 ${{ matrix.python }} • ${{ matrix.os }} • clang"
+    name: "🐍 ${{ matrix.python }} • ${{ matrix.os }} • clang-msvc"
 
     steps:
       - name: Show env
@@ -1264,13 +1265,14 @@ jobs:
       - name: Visibility test
         run: cmake --build . --target test_cross_module_rtti -j 2
 
-  windows_arm_msys2:
+  # Clang in MSYS2/MinGW-w64 CLANGARM64 toolchain + MSYS2 Python (Windows ARM)
+  windows_arm_clang_msys2:
     if: github.event.pull_request.draft == false
 
     runs-on: windows-11-arm
     timeout-minutes: 90
 
-    name: "🐍 3.12 • windows-11-arm • clang • msys2"
+    name: "🐍 3.12 • windows-11-arm • clang-msys2"
 
     defaults:
       run: