Update module github.com/prometheus/client_golang to v1.14.0 (#63)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Skip duplicate interfaces (#20)

Guard metric collection with nil checks (#10)

* Guard metric collection with nil checks

* Check for another nil value

* Fix formatting

* Add more nil guards

* Improve bool deref

* Improve timestamp conversion

* Add nil guards for label values

Co-authored-by: Alejandro Suárez <[email protected]>

Configure CI builds (#8)