security: Pin appleboy/ssh-action to specific commit SHA

Pin the ssh-action dependency to v1.2.4 (commit 823bd89e131d8d508129f9443cad5855e9ba96f0)
instead of using @master to address SonarCloud security hotspot.

Using a branch reference like @master is a security risk as the action
could be updated with malicious code at any time.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: cfsmp3

.github/workflows/sp-deployment-pipeline.yml

@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - name: Pre-deployment checks
-        uses: appleboy/ssh-action@master
+        uses: appleboy/ssh-action@823bd89e131d8d508129f9443cad5855e9ba96f0  # v1.2.4
         with:
           host: ${{ vars.PLATFORM_DOMAIN }}
           username: ${{ vars.SSH_USER }}
@@ -52,7 +52,7 @@ jobs:
             fi
 
       - name: Deploy application
-        uses: appleboy/ssh-action@master
+        uses: appleboy/ssh-action@823bd89e131d8d508129f9443cad5855e9ba96f0  # v1.2.4
         with:
           host: ${{ vars.PLATFORM_DOMAIN }}
           username: ${{ vars.SSH_USER }}
@@ -93,7 +93,7 @@ jobs:
 
       - name: Verify deployment
         id: health_check
-        uses: appleboy/ssh-action@master
+        uses: appleboy/ssh-action@823bd89e131d8d508129f9443cad5855e9ba96f0  # v1.2.4
         with:
           host: ${{ vars.PLATFORM_DOMAIN }}
           username: ${{ vars.SSH_USER }}
@@ -133,7 +133,7 @@ jobs:
 
       - name: Rollback on failure
         if: failure() && steps.health_check.outcome == 'failure'
-        uses: appleboy/ssh-action@master
+        uses: appleboy/ssh-action@823bd89e131d8d508129f9443cad5855e9ba96f0  # v1.2.4
         with:
           host: ${{ vars.PLATFORM_DOMAIN }}
           username: ${{ vars.SSH_USER }}
@@ -169,7 +169,7 @@ jobs:
 
       - name: Report deployment status
         if: always()
-        uses: appleboy/ssh-action@master
+        uses: appleboy/ssh-action@823bd89e131d8d508129f9443cad5855e9ba96f0  # v1.2.4
         with:
           host: ${{ vars.PLATFORM_DOMAIN }}
           username: ${{ vars.SSH_USER }}