Suppress warnings when using :deep, :slotted and :global

[RobinMalfait]

This PR ignores warnings related to :deep, :slotted and :global used by frameworks like Vue (see: https://vuejs.org/api/sfc-css-features#deep-selectors).

Test plan

Used a :deep() selector in a test project (Catalyst).

diff --git a/templates/catalyst/src/tailwind.css b/templates/catalyst/src/tailwind.css
index 79887e67..2acb749c 100644
--- a/templates/catalyst/src/tailwind.css
+++ b/templates/catalyst/src/tailwind.css
@@ -9,3 +9,7 @@
   --font-sans: Inter, sans-serif;
   --font-sans--font-feature-settings: 'cv11';
 }
+
+:deep(.foo) {
+  color: red;
+}

Before:

After:

Fixes: #18918 (comment)

[askomarov]

I upgraded to 4.1.15 and the warning didn't go away. What else needs to be done?

[RobinMalfait]

I upgraded to 4.1.15 and the warning didn't go away. What else needs to be done?

@askomarov Open a new issue with a minimal reproduction repo attached and we will take a look!