Fix typo from commit 4c5f855

Author: sezero

.github/workflows/main.yml

@@ -113,7 +113,7 @@ jobs:
           -DSDLMIXER_MOD_XMP=ON \
           -DSDLMIXER_MP3_MPG123=ON \
           -DSDLMIXER_OPUS=ON \
-          -SDLMIXER_VORBIS_VORBISFILE=ON \
+          -DSDLMIXER_VORBIS_VORBISFILE=ON \
           -DSDLMIXER_STRICT=ON \
           -DSDLMIXER_WERROR=ON \
           -DSDLMIXER_INSTALL_MAN=ON \