test: remove revealjs axe console/json cases that relied on link-name

The link-name violation from the slide-menu button is now fixed.
The console and json revealjs fixtures have no other detectable
violation, so remove those test cases. The document-mode fixtures
already have an unlabeled img that triggers image-alt.

Author: mcanouil

tests/integration/playwright/tests/axe-accessibility.spec.ts

@@ -50,18 +50,14 @@ const testCases: AxeTestCase[] = [
 
   // RevealJS — axe-check.js loads as standalone module (#13781).
   // RevealJS CSS transforms prevent axe-core from computing color contrast,
-  // so we check for link-name (slide-menu-button has unlabeled <a>).
+  // so we check for image-alt (unlabeled <img> on Slide 2).
   { format: 'revealjs', outputMode: 'document', url: '/revealjs/axe-accessibility.html',
-    expectedViolation: 'link-name' },
-  { format: 'revealjs', outputMode: 'console', url: '/revealjs/axe-console.html',
-    expectedViolation: 'link-name' },
-  { format: 'revealjs', outputMode: 'json', url: '/revealjs/axe-json.html',
-    expectedViolation: 'link-name' },
+    expectedViolation: 'image-alt' },
 
   // RevealJS dark theme — verifies CSS custom property bridge for theming.
   // Report should use --r-background-color/#191919, not the Sass fallback #fff.
   { format: 'revealjs-dark', outputMode: 'document', url: '/revealjs/axe-accessibility-dark.html',
-    expectedViolation: 'link-name' },
+    expectedViolation: 'image-alt' },
 
   // Dashboard — axe-check.js loads as standalone module, falls back to document.body (#13781)
   { format: 'dashboard', outputMode: 'document', url: '/dashboard/axe-accessibility.html',