Show protected branch rule names again (#23907)

`!important`s for one of the primary label selectors are removed by
#23774, so the repository branch protection settings ui will not have
the demanding css. This PR modifies `.ui.primary.label` to fix it.

Before:
<img width="1408" alt="飞书20230404-115410"
src="https://user-images.githubusercontent.com/17645053/229683221-ef9c7d5c-68a8-42b0-ba19-ef2d5dfce5f9.png">

After:
<img width="1419" alt="截屏2023-04-04 11 56 32"
src="https://user-images.githubusercontent.com/17645053/229683469-70cfc92d-d7ef-4323-a7f5-2247810fabce.png">

---------

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

web_src/css/base.css

@@ -2368,9 +2368,10 @@ a.ui.label:hover {
 }
 
 .ui.primary.label,
-.ui.primary.labels .label {
-  background-color: var(--color-primary) !important;
-  border-color: var(--color-primary-dark-2) !important;
+.ui.primary.labels .label, 
+.ui.ui.ui.primary.label {
+  background-color: var(--color-primary);
+  border-color: var(--color-primary-dark-2);
 }
 
 .ui.basic.labels .primary.label,