docs: remove bounty policy in favor of governance funding docs

CONTRIBUTING.md

@@ -8,6 +8,6 @@ There are additional docs describing [contributing documentation changes](./docs
 
 Testcontainers is [in the GitHub Sponsors program](https://github.com/sponsors/testcontainers)!
 
-This repository is supported by our sponsors, meaning that issues are eligible to have a 'bounty' attached to them by sponsors.
+This repository is supported by our sponsors. If you'd like to support the project, please consider sponsoring us via [GitHub Sponsors](https://github.com/sponsors/testcontainers) or [Open Collective](https://opencollective.com/testcontainers).
 
-Please see [the bounty policy page](https://www.testcontainers.org/bounty) if you are interested, either as a sponsor or as a contributor.
+To learn how funds are raised and distributed, see the [Testcontainers project funding policy](https://github.com/testcontainers/.github/blob/main/FUNDING.md). Financial matters are overseen by the Testcontainers Steering Committee, as described in the [project governance document](https://github.com/testcontainers/.github/blob/main/GOVERNANCE.md).

mkdocs.yml

@@ -137,7 +137,6 @@ nav:
     - Contributing:
           - contributing.md
           - contributing_docs.md
-          - bounty.md
 edit_uri: edit/main/docs/
 extra:
     latest_version: 2.0.5