Update CI - separate misspell, use re-usable action

Update the actions/checkout on the shellcheck. Install shellcheck
before trying to use. Use the client runners.

.github/workflows/misspell.yml

@@ -0,0 +1,22 @@
+name: Misspell
+on: 
+  push:
+  workflow_dispatch:
+
+# This allows a subsequently queued workflow run to interrupt previous runs
+concurrency:
+  group: perts-misspell-'${{ github.workflow }} @ ${{ github.event.pull_request.head.label || github.head_ref || github.ref }}'
+  cancel-in-progress: true
+
+jobs:
+  misspell:
+    runs-on: client
+    steps:
+        - name: Check out code
+          uses: actions/checkout@v4
+        - name: Remove folders we do not want to check (as we do not control them)
+          run: rm -rf node_modules vendor-licenses.txt
+        - name: Misspell
+          uses: PelionIoT/actions/.github/actions/misspell@main
+          with:
+            exceptions: "mosquitto"

.github/workflows/shellcheck.yml

@@ -11,26 +11,9 @@ concurrency:
   cancel-in-progress: true
 jobs:
   run-shellcheck:
-    runs-on: ubuntu-22.04
+    runs-on: client
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
+      - run: sudo apt-get update && sudo apt-get install -y shellcheck
       - run: shellcheck --version
       - run: shellcheck scripts/*.sh
-  run-misspell:
-    runs-on: ubuntu-22.04
-    steps:
-      - uses: actions/checkout@v3
-      - name: Run misspell
-        run: |
-            curl -L -o ./install-misspell.sh https://git.io/misspell
-            sh ./install-misspell.sh
-            bin/misspell -i mosquitto,Stichting,Mathematisch scripts test_cases test-configs utils conf >misspell.log
-            echo "### misspell" >>$SUMMARY_FILE
-            cat misspell.log >>$SUMMARY_FILE
-            bin/misspell -error -i mosquitto .
-            lines=$(wc -l < "misspell.log")
-            if [[ $lines -gt 0 ]]; then
-              echo "Misspell has findings, fail."
-              echo "TEST_FAIL=true" >> $GITHUB_ENV
-              exit 1
-            fi