Bump src/pi/mavros from b490957 to eac7b21

Bumps [src/pi/mavros](https://github.com/mavlink/mavros) from `b490957` to `eac7b21`.
- [Release notes](https://github.com/mavlink/mavros/releases)
- [Commits](mavlink/mavros@b490957...eac7b21)

---
updated-dependencies:
- dependency-name: src/pi/mavros
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>