robots changes

[dev-rajneeshkumar]

Please always provide the GitHub issue(s) your PR is for, as well as test URLs where your change can be observed (before and after):

Fix #

Test URLs:

• Before: https://main--moleculardevices--hlxsites.hlx.page/robots.txt
• After: https://robots--moleculardevices--hlxsites.hlx.page/robots.txt

[aem-code-sync]

Hello, I'm the AEM Code Sync Bot and I will run some test suites that validate the page speed.
In case there are problems, just click the checkbox below to rerun the respective action.

• Re-run PSI Checks

[aem-code-sync]

Page	Scores	Audits	Google
/robots.txt		Lighthouse returned error: NOT_HTML. The page provided is not HTML (served as MIME type text/plain).