With approval of RFC of removal of Internet Explorer 8 from basic browser support (“Grade C”) in T248061, it's time to get rid of all obsolete CSS hacks and fallbacks.
Acceptance criteria
- The following references should be removed or updated
https://codesearch.wmcloud.org/deployed/?q=(IE%20%3F%5B5678%5D%7CInternet%20Explorer%20%5B5678%5D)&i=nope&files=(.*)%5C.(css%7Cless)%24&excludeFiles=&repos= or more generally
https://codesearch.wmcloud.org/deployed/?q=(%20IE%7CInternet%20Explorer%20%5B5678%5D)&i=nope&files=(.*)%5C.(css%7Cless)%24&excludeFiles=&repos=
Note
- Ignore all MW core external libs, specifically jquery* ones
- Ignore DonationInterface Adyen Gateway styles
- Ignore Kartographer external libs
- Ignore LiquidThreads as it's unmaintained software