fix(tests): fix Cypress and PHP 8.4 CI failures

- Add Electron to supported browsers regex so Electron-based environments
  (including Cypress) are not redirected to the unsupported browser page.
  The browserslist-useragent-regexp 4.1.4 upgrade stopped matching Electron
  implicitly; this mirrors the existing AscDesktopEditor special-case.
- Fix TextProcessing mock: deleteOlderThan() returns int, not void.
  PHP 8.4 strict mock type enforcement causes a TypeError when the
  callback is declared void.

AI-Assisted-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: miaulalala

core/src/services/BrowsersListService.js

@@ -9,5 +9,6 @@ import browserslist from 'browserslist'
 import browserslistConfig from '@nextcloud/browserslist-config'
 
 // Generate a regex that matches user agents to detect incompatible browsers
-export const supportedBrowsersRegExp = new RegExp(getUserAgentRegex({ allowHigherVersions: true, browsers: browserslistConfig }).source + '|AscDesktopEditor')
+// Electron is added explicitly as it is used by Cypress tests and desktop app integrations
+export const supportedBrowsersRegExp = new RegExp(getUserAgentRegex({ allowHigherVersions: true, browsers: browserslistConfig }).source + '|AscDesktopEditor|Electron')
 export const supportedBrowsers = browserslist(browserslistConfig)

dist/7883-7883.js

@@ -160,10 +160,12 @@ protected function setUp(): void {
 		$this->taskMapper
 			->expects($this->any())
 			->method('deleteOlderThan')
-			->willReturnCallback(function (int $timeout): void {
+			->willReturnCallback(function (int $timeout): int {
+				$before = count($this->tasksDb);
 				$this->tasksDb = array_filter($this->tasksDb, function (array $task) use ($timeout) {
 					return $task['last_updated'] >= $this->currentTime->getTimestamp() - $timeout;
 				});
+				return $before - count($this->tasksDb);
 			});
 
 		$this->jobList = $this->createPartialMock(DummyJobList::class, ['add']);