Bump lib/CPP_PTB from 91e4d87 to f27cbc1

Bumps [lib/CPP_PTB](https://github.com/cpp-lln-lab/CPP_PTB) from `91e4d87` to `f27cbc1`.
- [Release notes](https://github.com/cpp-lln-lab/CPP_PTB/releases)
- [Commits](cpp-lln-lab/CPP_PTB@91e4d87...f27cbc1)

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

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

Author: dependabot[bot]