Add Google mailer

SMTP is the default provider to send email.
But users tend to use Gmail from time to time. So, instead of a complex installation to allow it, we prefer to ship it with the default package.

Also:
- update deps globally
- lock symfony/* deps to 4.4

.github/workflows/assets.yml

@@ -5,7 +5,7 @@ on:
   push:
     branches:
       - master
-      - 2.*
+      - "2.**"
 
 permissions:
   contents: read

.github/workflows/coding-standards.yml

@@ -5,7 +5,7 @@ on:
   push:
     branches:
       - master
-      - 2.*
+      - "2.**"
 
 permissions:
   contents: read

.github/workflows/continuous-integration.yml

@@ -5,7 +5,7 @@ on:
   push:
     branches:
       - master
-      - 2.*
+      - "2.**"
 
 env:
   PGPASSWORD: wallabagrocks

.github/workflows/translations.yml

@@ -5,7 +5,7 @@ on:
   push:
     branches:
       - master
-      - 2.*
+      - "2.**"
 
 permissions:
   contents: read

composer.json

@@ -129,6 +129,7 @@
         "symfony/finder": "^4.4",
         "symfony/form": "^4.4",
         "symfony/framework-bundle": "^4.4",
+        "symfony/google-mailer": "^4.4",
         "symfony/http-foundation": "^4.4",
         "symfony/http-kernel": "^4.4",
         "symfony/mailer": "^4.4",
@@ -209,7 +210,11 @@
         "incenteev-parameters": {
             "file": "app/config/parameters.yml"
         },
-        "public-dir": "web"
+        "public-dir": "web",
+        "symfony": {
+            "allow-contrib": true,
+            "require": "4.4.*"
+        }
     },
     "scripts": {
         "post-install-cmd": [