chore: remove Trivy scan (cloudnative-pg#10344)

Remove the Trivy vulnerability scanner workflow and the Trivy step from
the continuous integration workflow.

Closes cloudnative-pg#10343

Signed-off-by: Jonathan Gonzalez V. <jonathan.gonzalez@enterprisedb.com>
Signed-off-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>
Co-authored-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>
(cherry picked from commit ab147df)

Author: sxd

.github/workflows/continuous-integration.yml

@@ -641,16 +641,6 @@ jobs:
           image: ${{ env.CONTROLLER_IMG }}
           args: --severity-threshold=high --file=Dockerfile --username=${{ env.REGISTRY_USER }} --password=${{ env.REGISTRY_PASSWORD }}
 
-      - name: Run Trivy to check Docker image for vulnerabilities
-        uses: aquasecurity/trivy-action@57a97c7e7821a5776cebc9bb87c984fa69cba8f1 # 0.35.0
-        if: env.PUSH == 'true'
-        id: trivy
-        continue-on-error: true
-        with:
-          version: 'latest'
-          image-ref: ${{ env.CONTROLLER_IMG }}
-          format: 'table'
-
       - name: Install cosign
         if: |
           env.SIGN_IMAGES == 'true' &&