fix: Add try except for force download

[Pringled]

This PR adds a try except to the model loading, falling back to force_download=True in case it fails for any reason. Closes #222.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Files with missing lines	Coverage Δ
src/semble/index/dense.py	100.00% <100.00%> (ø)
src/semble/version.py	100.00% <100.00%> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[greptile-apps]

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

_{Reviews (1): Last reviewed commit: "Add try except for force download" | Re-trigger Greptile}