build: add shell script linter workflow

Implement workflow to to run static analysis and linting of all shell
scripts by using shfmt and shellcheck.

Fixes: #5396

Signed-off-by: Ruslan Mstoi <ruslan.mstoi@intel.com>

.github/workflows/shlint.yaml

@@ -0,0 +1,20 @@
+name: Shell scripts check
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  sh-checker:
+    name: Check shell scripts
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+    - name: Run the shell script checkers
+      uses: luizm/action-sh-checker@master
+      env:
+        SHFMT_OPTS: -i 4 -d
+        SHELLCHECK_OPTS: -x --source-path scripts