fix: use `<time>` tag

[scarf005]

What does this PR change? What problem does it solve?

replaces usage of <span> in datetime format to <time>. using time tag helps accessibility (e.g for screen readers) by adding a semantic token for times.

Was the change discussed in an issue or in the Discussions before?

i haven't, as it seemed like a tiny change.

PR Checklist

• [ ] This change adds/updates translations and I have used the template present here.
• [x] I have enabled maintainer edits for this PR.
• [x] I have verified that the code works as described/as intended.
• [ ] This change adds a Social Icon which has a permissive license to use it.
• [x] This change does not include any CDN resources/links.
• [x] This change does not include any unrelated scripts such as bash and python scripts.
• [ ] This change updates the overridden internal templates from HUGO's repository.

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud