build(deps): bump falco_plugin from 0.4.3 to 0.5.1 in /plugins/dummy_rs

Bumps [falco_plugin](https://github.com/falcosecurity/plugin-sdk-rs) from 0.4.3 to 0.5.1.
- [Release notes](https://github.com/falcosecurity/plugin-sdk-rs/releases)
- [Commits](falcosecurity/plugin-sdk-rs@v0.4.3...v0.5.1)

---
updated-dependencies:
- dependency-name: falco_plugin
  dependency-version: 0.5.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Signed-off-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Signed-off-by: Leonardo Di Giovanna <[email protected]>

Author: dependabot[bot]