docs: fix typos in typings, tests, and core comments

- addon-clipboard: "Note that this" instead of duplicate "this"
- addon-webgl: remove stray "the" before "a" in event JSDoc
- SharedRendererTests: duplicate "the" in test title
- Types: "protocol" spelling in CoreMouseEncoding JSDoc
- InputHandler: "a replacement char" article fix

Co-authored-by: Cursor <cursoragent@cursor.com>

test/playwright/SharedRendererTests.ts

@@ -980,7 +980,7 @@ export function injectSharedRendererTests(ctx: ISharedRendererTestContext): void
   });
 
   test.describe('selectionInactiveBackground', async () => {
-    test('should render the the inactive selection when not focused', async () => {
+    test('should render the inactive selection when not focused', async () => {
       const theme: ITheme = {
         selectionBackground: '#FF000080',
         selectionInactiveBackground: '#0000FF80'