hard coded sandbox tag

Author: nhsd-david-wass

.github/actions/build-sandbox/action.yml

@@ -52,7 +52,7 @@ runs:
       working-directory: ./sandbox
       run: |
           proxygen docker get-login | bash
-          docker build -t nhs-notify-supplier:latest .
-          IMAGE_ID=$(docker images -q nhs-notify-supplier:latest)
-          docker tag $IMAGE_ID 958002497996.dkr.ecr.eu-west-2.amazonaws.com/nhs-notify-supplier:latest
-          docker push 958002497996.dkr.ecr.eu-west-2.amazonaws.com/nhs-notify-supplier:latest
+          docker build -t nhs-notify-supplier:pr99 .
+          IMAGE_ID=$(docker images -q nhs-notify-supplier:pr99)
+          docker tag $IMAGE_ID 958002497996.dkr.ecr.eu-west-2.amazonaws.com/nhs-notify-supplier:pr99
+          docker push 958002497996.dkr.ecr.eu-west-2.amazonaws.com/nhs-notify-supplier:pr99

specification/api/components/x-nhsd-apim/target-sandbox.yml

@@ -4,7 +4,7 @@ containers:
   - name: nhs-notify-supplier
     image:
       name: nhs-notify-supplier
-      tag: latest
+      tag: pr99
     environment:
       LOG_LEVEL: info
       NODE_ENV: development