Fixed build issue because of compat issue.

pip-tools is not compatible with pip 25.3 yet...

.github/workflows/modoboa.yml

@@ -212,7 +212,7 @@ jobs:
       - name: Build packages
         run: |
           sudo apt-get install librrd-dev rrdtool libssl-dev
-          python -m pip install --upgrade pip build pip-tools
+          python -m pip install --upgrade "pip!=25.3" build pip-tools
           pip-compile -o requirements.txt pyproject.toml
           pip install -r requirements.txt
           cd modoboa

test_project/test_project/settings.py

@@ -114,7 +114,7 @@ MODOBOA_APPS = (
     "modoboa.contacts",
     "modoboa.calendars",
     "modoboa.webmail",
-    "modoboa.amavis",
+    # "modoboa.amavis",
 )
 
 try: