Bump lib/CPP_PTB from 06fd8eb to fdbbfdf

Bumps [lib/CPP_PTB](https://github.com/cpp-lln-lab/CPP_PTB) from `06fd8eb` to `fdbbfdf`.
- [Release notes](https://github.com/cpp-lln-lab/CPP_PTB/releases)
- [Commits](cpp-lln-lab/CPP_PTB@06fd8eb...fdbbfdf)

---
updated-dependencies:
- dependency-name: lib/CPP_PTB
  dependency-type: direct:production
...

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

Author: dependabot[bot]