ci: fix filters for smoke-tests job

[pkanal]

Which problem is this PR solving?

Added filters for smoke-tests job because CircleCI needs filters for every job if there are filters for a single job. This was preventing other steps like publish-github.

Short description of the changes

• Added a filters section that allows smoke tests to run on every push.

How to verify that this has the expected result

• Smoke tests should run in CI: https://github.com/honeycombio/honeycomb-opentelemetry-go/pull/110/checks?check_run_id=10760320583