servo: Ignore more flaky font tests

Source-Repo: https://github.com/servo/servo
Source-Revision: de59f7ef861dff855660dcac5f5851d3a239f58c

servo/src/servo/text/font.rs

@@ -284,6 +284,7 @@ fn should_destruct_on_fail_without_leaking() {
 
 fn should_get_glyph_indexes() {
     #[test];
+    #[ignore(reason = "random failures")];
 
     let font = create_test_font();
     let glyph_idx = font.glyph_idx('w');

servo/src/servo/text/shaper.rs

@@ -143,6 +143,7 @@ fn hb_glyph_pos_to_servo_glyph_pos(hb_pos: &hb_glyph_position_t) -> GlyphPos {
 
 fn should_get_glyph_indexes() {
     #[test];
+    #[ignore(reason = "random failures")];
 
     let font = font::create_test_font();
     let glyphs = shape_text(&font, "firecracker");