ci: add PostgreSQL and MySQL dependency setup steps to sqlness job (#8185)

* Migrate sqlness CI dependencies to services

* Clarify sqlness kafka readiness wait

* Normalize sqlness MySQL job name

* Refactor sqlness CI to reuse setup actions

* Describe reusable sqlness setup actions

* Clarify MySQL setup action usage

* Update sqlness workflow setup steps

* Decouple sqlness docker setup from cluster actions

* Align postgres docker setup with dependency pulls

* Revert nonessential setup action edits

* Revert setup action files to main state

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

.github/workflows/develop.yml

@@ -669,18 +669,28 @@ jobs:
           - name: "Basic"
             opts: ""
             kafka: false
+            postgres: false
+            mysql: false
           - name: "Remote WAL"
             opts: "-w kafka -k 127.0.0.1:9092"
             kafka: true
+            postgres: false
+            mysql: false
           - name: "PostgreSQL KvBackend"
-            opts: "--setup-pg"
+            opts: "--setup-pg postgresql://greptimedb:admin@127.0.0.1:5432/postgres"
             kafka: false
-          - name: "MySQL Kvbackend"
-            opts: "--setup-mysql"
+            postgres: true
+            mysql: false
+          - name: "MySQL KvBackend"
+            opts: "--setup-mysql mysql://greptimedb:admin@127.0.0.1:3306/mysql"
             kafka: false
+            postgres: false
+            mysql: true
           - name: "Flat format"
             opts: "--enable-flat-format"
             kafka: false
+            postgres: false
+            mysql: false
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v4
@@ -688,9 +698,19 @@ jobs:
           persist-credentials: false
 
       - if: matrix.mode.kafka
-        name: Setup kafka server
+        name: Setup Kafka
         working-directory: tests-integration/fixtures
-        run:  ../../.github/scripts/pull-test-deps-images.sh && docker compose up -d --wait kafka
+        run: ../../.github/scripts/pull-test-deps-images.sh && docker compose up -d --wait kafka
+
+      - if: matrix.mode.postgres
+        name: Setup PostgreSQL
+        working-directory: tests-integration/fixtures
+        run: ../../.github/scripts/pull-test-deps-images.sh && docker compose up -d --wait postgres
+
+      - if: matrix.mode.mysql
+        name: Setup MySQL
+        working-directory: tests-integration/fixtures
+        run: ../../.github/scripts/pull-test-deps-images.sh && docker compose up -d --wait mysql
 
       - name: Download pre-built binaries
         uses: actions/download-artifact@v4