update gzdoom build script

do shallow clone only when run inside github actions workflow
remove unused variable
rename script file

build_gzdoom

@@ -7,7 +7,11 @@ DEPS_DIR=$(cd "${0%/*}"; pwd)/
 cd "${DEPS_DIR}"
 
 if [ ! -e gzdoom ]; then
-	git clone --depth 1 https://github.com/coelckers/gzdoom.git
+	if [ ! -z "${GITHUB_ACTIONS}" ]; then
+		GIT_CLONE_OPTIONS="--depth 1"
+	fi
+	
+	git clone ${GIT_CLONE_OPTIONS} https://github.com/coelckers/gzdoom.git
 fi
 
 cd gzdoom
@@ -17,20 +21,19 @@ if [ ! -e build ]; then
 	mkdir build
 fi
 
+cd build
+export PATH=$PATH:/Applications/CMake.app/Contents/bin
+
 OPENAL_DIR=${DEPS_DIR}openal/
 ZMUSIC_DIR=${DEPS_DIR}zmusic/
 OPENAL_DIR=${DEPS_DIR}openal/
 JPEG_DIR=${DEPS_DIR}jpeg/
-SDL_DIR=${DEPS_DIR}sdl/
 FLUIDSYNTH_LIBS=${DEPS_DIR}fluidsynth/lib/libfluidsynth.a\ ${DEPS_DIR}fluidsynth/lib/libglib-2.0.a\ ${DEPS_DIR}fluidsynth/lib/libintl.a
 SNDFILE_LIBS=${DEPS_DIR}ogg/lib/libogg.a\ ${DEPS_DIR}vorbis/lib/libvorbis.a\ ${DEPS_DIR}vorbis/lib/libvorbisenc.a\ ${DEPS_DIR}flac/lib/libFLAC.a\ ${DEPS_DIR}sndfile/lib/libsndfile.a
 EXTRA_LIBS=-liconv\ ${DEPS_DIR}mpg123/lib/libmpg123.a\ ${FLUIDSYNTH_LIBS}\ ${SNDFILE_LIBS}
 FRAMEWORKS=-framework\ AudioUnit\ -framework\ AudioToolbox\ -framework\ Carbon\ -framework\ CoreAudio\ -framework\ CoreMIDI\ -framework\ CoreVideo\ -framework\ ForceFeedback
 LINKER_FLAGS=${EXTRA_LIBS}\ ${FRAMEWORKS}
 
-cd build
-export PATH=$PATH:/Applications/CMake.app/Contents/bin
-
 cmake                                                 \
 	-DCMAKE_BUILD_TYPE="Release"                      \
 	-DCMAKE_OSX_DEPLOYMENT_TARGET="10.9"              \
@@ -46,6 +49,6 @@ cmake                                                 \
 	-DJPEG_INCLUDE_DIR="${JPEG_DIR}include"           \
 	-DJPEG_LIBRARY="${JPEG_DIR}lib/libjpeg.a"         \
 	..
-make -j2
+make -j3
 
 cp "${DEPS_DIR}moltenvk/lib/libMoltenVK.dylib" "gzdoom.app/Contents/MacOS/"