Extension errors without a git repository

**Describe the bug**
Without a `.git` config the extension searches for "//.config" and errors continuously with "[UriError]: If a URI does not contain an authority component, then the path cannot begin with two slash characters ("//")"

**Expected behaviour**
No errors

**Actual behaviour**
Many errors

**Debugging information**
 - Ubuntu 24.04.1 LTS
 - Theme Check Version [3.5.0, 3.4.0]
