Try to avoid passwords in clean text

.github/workflows/cloud-regress.yml

@@ -51,6 +51,19 @@ jobs:
           cd /__w/neon/neon/vendor/postgres-v${{ matrix.DEFAULT_PG_VERSION }}
           patch -p1 < ../../patches/cloud_regress_pg${{ matrix.DEFAULT_PG_VERSION }}.patch
 
+      - name: Generate a random password
+        id: pwgen
+        run: |
+          DBPASS=$(dd if=/dev/random bs=48 count=1 2>/dev/null | base64)
+          echo DBPASS=${DBPASS//\//} >> ${GITHUB_OUTPUT}
+
+      - name: Change tests according to the generated password
+        run: |
+          cd /__w/neon/neon/vendor/postgres-v${{ matrix.DEFAULT_PG_VERSION }}
+          for fname in sql/*.sql expected/*.out; do
+          sed -i.bak "s/NEON_PASSWORD_PLACEHOLDER/'$dbpassword'/" $file
+          done
+
       - name: Download Neon artifact
         uses: ./.github/actions/download
         with: