Fix dead QUEUE_DRIVER env var name in templates and test config

`config/queue.php` reads `env('QUEUE_CONNECTION', 'sync')` since the
Laravel Shift in v6.0.0 (commit cc3c59bf97), but seven .env templates
and phpunit.xml still set `QUEUE_DRIVER` — the old Laravel <5.7 name
that the framework no longer reads. The default is `sync` anyway so
the gap is silent; but anyone copying these templates and trying to
enable an async driver (redis, database, beanstalkd, sqs) finds their
setting silently ignored.

Rename across:
- .env.example
- .env.docker
- .env.dev.docker
- .env.dusk.example
- docker/docker-secrets.env
- docker/docker.env
- phpunit.xml (XML <env> tag)

No code change. Default value `sync` preserved everywhere.

---
Disclosure: drafted with a coding agent's help.

Signed-off-by: Sebastian Mendel <info@sebastianmendel.de>

.env.dev.docker

@@ -113,7 +113,7 @@ ENABLE_HSTS=false
 # --------------------------------------------
 CACHE_DRIVER=file
 SESSION_DRIVER=file
-QUEUE_DRIVER=sync
+QUEUE_CONNECTION=sync
 CACHE_PREFIX=snipeit
 
 # --------------------------------------------

.env.docker

@@ -120,7 +120,7 @@ ENABLE_HSTS=false
 # --------------------------------------------
 CACHE_DRIVER=file
 SESSION_DRIVER=file
-QUEUE_DRIVER=sync
+QUEUE_CONNECTION=sync
 CACHE_PREFIX=snipeit
 
 # --------------------------------------------

.env.dusk.example

@@ -72,7 +72,7 @@ CORS_ALLOWED_ORIGINS="*"
 # --------------------------------------------
 CACHE_DRIVER=file
 SESSION_DRIVER=file
-QUEUE_DRIVER=sync
+QUEUE_CONNECTION=sync
 
 # --------------------------------------------
 # OPTIONAL: LOGIN THROTTLING

.env.example

@@ -142,7 +142,7 @@ ENABLE_HSTS=false
 # OPTIONAL: CACHE SETTINGS
 # --------------------------------------------
 CACHE_DRIVER=file
-QUEUE_DRIVER=sync
+QUEUE_CONNECTION=sync
 CACHE_PREFIX=snipeit
 
 # --------------------------------------------

docker/docker-secrets.env

@@ -51,4 +51,4 @@ SECURE_COOKIES=false
 # --------------------------------------------
 CACHE_DRIVER=file
 SESSION_DRIVER=file
-QUEUE_DRIVER=sync
+QUEUE_CONNECTION=sync

docker/docker.env

@@ -60,4 +60,4 @@ SECURE_COOKIES=false
 # --------------------------------------------
 CACHE_DRIVER=file
 SESSION_DRIVER=file
-QUEUE_DRIVER=sync
+QUEUE_CONNECTION=sync

phpunit.xml

@@ -23,7 +23,7 @@
     <env name="CACHE_DRIVER" value="array"/>
     <env name="MAIL_FROM_ADDR" value="app@example.com"/>
     <env name="MAIL_MAILER" value="array"/>
-    <env name="QUEUE_DRIVER" value="sync"/>
+    <env name="QUEUE_CONNECTION" value="sync"/>
     <env name="SESSION_DRIVER" value="array"/>
     <ini name="display_errors" value="true"/>
   </php>