Set pytest.fixture scope to class, add Swarm E2E tests, and update Docker Swarm configurations

- Modified `pytest.fixture` scope to `class` across tests to improve fixture lifecycle and reduce setup overhead.
- Introduced a new `tests_e2e/test_swarm.py` test suite for Docker Swarm stack configurations.
- Added E2E tests for Swarm mode with scenarios such as basic services and combined plugins.
- Updated HAProxy image in Swarm stack `.yml` files to `byjg/easy-haproxy:local` for local testing consistency.
- Added `swarm` marker in `pyproject.toml` for differentiating Docker Swarm-specific tests.
- Updated GitHub workflows to include a new Swarm E2E test pipeline.

tests_e2e/swarm/cloudflare.yml

@@ -70,7 +70,7 @@ version: "3.7"
 
 services:
   haproxy:
-    image: byjg/easy-haproxy:5.0.0
+    image: byjg/easy-haproxy:local
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock
     configs:

tests_e2e/swarm/easyhaproxy.yml

@@ -54,7 +54,7 @@
 
 services:
   haproxy:
-    image: byjg/easy-haproxy:5.0.0
+    image: byjg/easy-haproxy:local
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock
       - ./certs:/certs/haproxy

tests_e2e/swarm/ip-whitelist.yml

@@ -65,7 +65,7 @@ version: "3.7"
 
 services:
   haproxy:
-    image: byjg/easy-haproxy:5.0.0
+    image: byjg/easy-haproxy:local
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock
     deploy:

tests_e2e/swarm/jwt-validator.yml

@@ -78,7 +78,7 @@ version: "3.7"
 
 services:
   haproxy:
-    image: byjg/easy-haproxy:5.0.0
+    image: byjg/easy-haproxy:local
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock
     configs:

tests_e2e/swarm/plugins-combined.yml

@@ -94,7 +94,7 @@ version: "3.7"
 
 services:
   haproxy:
-    image: byjg/easy-haproxy:5.0.0
+    image: byjg/easy-haproxy:local
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock
     configs: