github/workflows: drop clang32

It's being dropped upstream* and recently lua51 was removed along with
luajit*. mingw32 already covers 32-bit support, and it's not like we're
in dire need of this so just remove it.

*: 89521b9f8d
*: 947a8592ca

.github/workflows/build.yml

@@ -501,7 +501,6 @@ jobs:
       fail-fast: false
       matrix:
         sys:
-          - clang32
           - clang64
           - mingw32
           - mingw64
@@ -541,7 +540,7 @@ jobs:
             vulkan-devel:p
 
       - name: Install dependencies
-        if: ${{ matrix.sys != 'clang32' && matrix.sys != 'mingw32' }}
+        if: ${{ matrix.sys != 'mingw32' }}
         run: |
           pacboy --noconfirm -S angleproject cppwinrt libcdio-paranoia rst2pdf \
                                 rubberband uchardet vapoursynth