CI, OpenWatcom: remove workaround now that setup-watcom is fixed.

.github/workflows/watcom.yml

@@ -16,8 +16,6 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - uses: open-watcom/setup-watcom@v0
-        with:
-          tag: 2022-05-01-Build
       - name: Build SDL2
         run: |
           wmake -f ${{ matrix.platform.makefile }}