[chore] Add fossa badges

[thompson-tomo]

Changes

Adds fossa badges to project readme

[!IMPORTANT] Pull requests acceptance are subject to the triage process as described in Issue and PR Triage Management. PRs that do not follow the guidance above, may be automatically rejected and closed.

Merge requirement checklist

• [x] CONTRIBUTING.md guidelines followed.
• [ ] Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• [ ] Links to the prototypes or existing instrumentations (when adding or changing conventions)

[github-actions[bot]]

This PR was marked stale due to lack of activity. It will be closed in 7 days.

[trask]

Closing, we haven't fully rolled out FOSSA yet (https://github.com/open-telemetry/community/issues/2574)