Fix tests and move to 7.3 as a min php version

Signed-off-by: Julius Härtl <jus@bitgrid.net>

.github/workflows/lint.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        php-versions: ['7.2', '7.3', '7.4']
+        php-versions: ['7.3', '7.4']
 
     name: php${{ matrix.php-versions }} lint
     steps:

composer.json

@@ -13,14 +13,17 @@
 	},
 	"require-dev": {
 		"roave/security-advisories": "dev-master",
-		"christophwurst/nextcloud": "^21@dev",
-		"phpunit/phpunit": "^9",
+		"christophwurst/nextcloud": "^22@dev",
+		"phpunit/phpunit": "^8",
 		"nextcloud/coding-standard": "^0.5.0",
 		"symfony/event-dispatcher": "^4.0",
 		"vimeo/psalm": "^4.3",
 		"php-parallel-lint/php-parallel-lint": "^1.2"
 	},
 	"config": {
+		"platform": {
+			"php": "7.3"
+		},
 		"optimize-autoloader": true,
 		"classmap-authoritative": true
 	},

tests/unit/Service/BoardServiceTest.php

@@ -263,6 +263,9 @@ class BoardServiceTest extends TestCase {
 			->willReturn([
 				'admin' => 'admin',
 			]);
+		$this->boardMapper->expects($this->once())
+			->method('find')
+			->willReturn(new Board());
 		$this->assertEquals($acl, $this->service->addAcl(
 			123, 'user', 'admin', true, true, true
 		));
@@ -352,6 +355,9 @@ class BoardServiceTest extends TestCase {
 		$acl->resolveRelation('participant', function ($participant) use (&$user) {
 			return null;
 		});
+		$this->boardMapper->expects($this->once())
+			->method('find')
+			->willReturn(new Board());
 		$this->permissionService->expects($this->any())
 			->method('findUsers')
 			->willReturn([