github-actions: kernelci-trigger: Add skip_ltp input and metadata support

Add skip_ltp input to the trigger workflow alongside the existing
skip_kabi and skip_kselftests inputs. Validate, pass through env,
and save to pr_metadata/skip_ltp.txt so the main workflow can read
it via the pre-setup job's artifact-based metadata.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Shreeya Patel <spatel@ciq.com>

Author: shreeya-patel98

.github/workflows/kernel-build-and-test-multiarch-trigger.yml

@@ -18,6 +18,11 @@ on:
         required: false
         type: boolean
         default: false
+      skip_ltp:
+        description: 'Skip the LTP test stage'
+        required: false
+        type: boolean
+        default: false
 
 permissions:
   contents: read
@@ -44,6 +49,7 @@ jobs:
           ARCHITECTURES: ${{ inputs.architectures }}
           SKIP_KABI: ${{ inputs.skip_kabi }}
           SKIP_KSELFTESTS: ${{ inputs.skip_kselftests }}
+          SKIP_LTP: ${{ inputs.skip_ltp }}
           COMMIT_MSG: ${{ github.event.head_commit.message }}
           PR_TITLE: ${{ github.event.pull_request.title }}
         run: |
@@ -138,6 +144,12 @@ jobs:
             exit 1
           fi
 
+          # Validate skip_ltp - must be exactly 'true' or 'false'
+          if ! [[ "$SKIP_LTP" =~ ^(true|false)$ ]]; then
+            echo "❌ Invalid skip_ltp value: $SKIP_LTP"
+            exit 1
+          fi
+
           # Pass validated values to environment
           echo "IS_PR=$IS_PR" >> "$GITHUB_ENV"
           echo "BASE_REF=$BASE_REF" >> "$GITHUB_ENV"
@@ -146,6 +158,7 @@ jobs:
           echo "ARCHITECTURES=$ARCHITECTURES" >> "$GITHUB_ENV"
           echo "SKIP_KABI=$SKIP_KABI" >> "$GITHUB_ENV"
           echo "SKIP_KSELFTESTS=$SKIP_KSELFTESTS" >> "$GITHUB_ENV"
+          echo "SKIP_LTP=$SKIP_LTP" >> "$GITHUB_ENV"
 
       - name: Clone base branch
         if: github.event_name == 'pull_request'
@@ -194,6 +207,7 @@ jobs:
             echo "$ARCHITECTURES" > pr_metadata/architectures.txt
             echo "$SKIP_KABI" > pr_metadata/skip_kabi.txt
             echo "$SKIP_KSELFTESTS" > pr_metadata/skip_kselftests.txt
+            echo "$SKIP_LTP" > pr_metadata/skip_ltp.txt
             echo "$IS_PR" > pr_metadata/is_pr.txt
 
             # Create a checksum of metadata for integrity verification