ci: wrap matrix values within quotes

Author: Belco90

.github/workflows/pipeline.yml

@@ -53,8 +53,8 @@ jobs:
 
     strategy:
       matrix:
-        node: [ 10.12, 10, 12.0, 12, 14 ]
-        eslint: [ 7.5, 7 ]
+        node: [ '10.12', '10', '12.0', '12', '14' ]
+        eslint: [ '7.5', '7' ]
 
     steps:
       - name: Cancel Previous Runs