build: check eglext.h header version

We use EGL_EXT_device_drm_render_node, which has been introduced
here:
53f038f6fd

render/meson.build

@@ -27,6 +27,20 @@ internal_config.set10('HAVE_EVENTFD', cc.has_header('sys/eventfd.h'))
 
 if 'gles2' in renderers or 'auto' in renderers
 	egl = dependency('egl', required: 'gles2' in renderers)
+	if egl.found()
+		eglext_version = cc.get_define(
+			'EGL_EGLEXT_VERSION',
+			dependencies: egl,
+			prefix: '#include <EGL/eglext.h>',
+		).to_int()
+		if eglext_version < 20210604
+			egl = dependency(
+				'',
+				required: 'gles2' in renderers,
+				not_found_message: 'EGL headers too old',
+			)
+		endif
+	endif
 	gbm = dependency('gbm', required: 'gles2' in renderers)
 	if egl.found() and gbm.found()
 		wlr_deps += [egl, gbm]