Pressing Enter when searching reloads current page

This is most likely an upstream issue with MkDocs Material and we should report it there (or see if it's already been fixed).

Steps to reproduce:

1. Go to a documentation page
2. Enter a search term in the search bar
3. Note that it usually takes a while to see results
4. Press Enter (maybe because you're not sure if the search is actually running)
5. Expect nothing to happen after pressing Enter
6. Observe that the search is canceled and the current page is reloaded.

ref: https://chat.civicrm.org/civicrm/pl/co9zoo34r7rp3f5oyoofk4rqhe