fix GH Actions test run on Linux

tests/test_linux.sh

@@ -8,5 +8,5 @@ build linux_gles3_debug SOKOL_GLES3 Debug
 build linux_gles3_release SOKOL_GLES3 Release
 build_force_egl linux_gl_egl_debug SOKOL_GLCORE33 Debug
 build_force_egl linux_gl_egl_release SOKOL_GLCORE33 Release
-runtest linux_glx_debug
+runtest linux_gl_debug