CI/Appimage: Suppress error when no tags are present

.github/workflows/scripts/linux/appimage-qt.sh

@@ -206,7 +206,7 @@ GIT_VERSION=$(git tag --points-at HEAD)
 
 if [[ "${GIT_VERSION}" == "" ]]; then
 	# In the odd event that we run this script before the release gets tagged.
-	GIT_VERSION=$(git describe --tags)
+	GIT_VERSION=$(git describe --tags || true)
 	if [[ "${GIT_VERSION}" == "" ]]; then
 		GIT_VERSION=$(git rev-parse HEAD)
 	fi

pcsx2/DebugTools/SymbolGuardian.h

@@ -6,6 +6,7 @@
 #include <atomic>
 #include <thread>
 #include <functional>
+#include <mutex>
 #include <shared_mutex>
 
 #include <ccc/ast.h>