Add tests for files users might not see, but crawlers use

[holly-cummins]

Slightly closing the barn door after the #2958 horse, but regressions here would be hard for users to spot.

[quarkus-bot]

Status for workflow Build

This is the status report for running Build on commit 120d16d.

Failing Jobs

Status	Name	Step	Failures	Logs	Raw logs
❌	Build	Run smoke tests	Failures	Logs	Raw logs

Full information is available in the Build summary check run.

Failures

⚙️ Build #

- Failing: Root module 

📦 Root module

❌ io.quarkusio.SitemapTest.sitemapHtmlContainsLinks line 146 - More details - Source on GitHub

Details

org.opentest4j.AssertionFailedError: sitemap.html should contain anchor links ==> expected: <true> but was: <false>
	at org.junit.jupiter.api.Assertions.assertTrue(Assertions.java:232)
	at io.quarkusio.SitemapTest.sitemapHtmlContainsLinks(SitemapTest.java:146)

❌ io.quarkusio.SitemapTest.sitemapHtmlReturns200 line 131 - More details - Source on GitHub

Details

org.opentest4j.AssertionFailedError: Expected 200 for /sitemap.html but got 404 ==> expected: <200> but was: <404>
	at org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:601)
	at io.quarkusio.SitemapTest.sitemapHtmlReturns200(SitemapTest.java:131)