CI: change Node.js to 14 (#32796)

This is so that it's consistent with the JS workflow thus the cache should match.

.github/workflows/browserstack.yml

@@ -5,7 +5,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   browserstack:

.github/workflows/bundlewatch.yml

@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   bundlewatch:

.github/workflows/css.yml

@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   css:

.github/workflows/dart-sass.yml

@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   css:

.github/workflows/docs.yml

@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   docs:

.github/workflows/lint.yml

@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   lint: