test(glossary): mark Glossary Terms column-selection spec as slow to fix 60s timeout flake (#29603)

The "Column selection and visibility for Glossary Terms table" test
intermittently times out at the default 60s in the nightly upgrade runs
(e.g. open-metadata/openmetadata-nightly run 28412262801, shard 4). The
test performs four column-toggle + page.reload() cycles; on a heavily
populated instance the post-reload glossary page can take longer than 60s
to render the terms table, so the final verifyAllColumns() assertion times
out.

Add test.slow(true) (3x timeout -> 180s) to match the rest of the tests in
this describe block, which already use it.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: siddhant1

openmetadata-ui/src/main/resources/ui/playwright/e2e/Pages/Glossary.spec.ts

@@ -1523,6 +1523,7 @@ test.describe('Glossary tests', () => {
   test('Column selection and visibility for Glossary Terms table', async ({
     browser,
   }) => {
+    test.slow(true);
     const { page, afterAction, apiContext } = await performAdminLogin(browser);
     const glossary1 = new Glossary();
     const glossaryTerm1 = new GlossaryTerm(glossary1);