Bumped Spellcheck GHA to latest release (#44)

Author: jonasbn

.github/workflows/spellcheck.yaml

@@ -7,5 +7,5 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@master
-    - uses: rojopolis/spellcheck-github-actions@0.16.0
+    - uses: rojopolis/spellcheck-github-actions@0.26.0
       name: Spellcheck