fix GitHub CI plugin warnings (#121)

* fix GitHub CI plugin warnings

Signed-off-by: Cocoa <i@uwucocoa.moe>

---------

Signed-off-by: Cocoa <i@uwucocoa.moe>

Author: cocoa-xu

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ concurrency:
 
 jobs:
   linux:
-    if: "!contains(github.event.pull_request.labels.*.name, 'skip ci')"
+    if: contains(github.event.pull_request.labels.*.name, 'skip ci') != true
     runs-on: ubuntu-20.04
     env:
       MIX_ENV: test
@@ -46,7 +46,7 @@ jobs:
           mix test
 
   windows:
-    if: "!contains(github.event.pull_request.labels.*.name, 'skip ci')"
+    if: contains(github.event.pull_request.labels.*.name, 'skip ci') != true
     runs-on: windows-latest
     env:
       MIX_ENV: test
@@ -69,7 +69,7 @@ jobs:
           mix test --exclude postgresql
 
   macos:
-    if: "!contains(github.event.pull_request.labels.*.name, 'skip ci')"
+    if: contains(github.event.pull_request.labels.*.name, 'skip ci') != true
     runs-on: macos-13
     env:
       MIX_ENV: test