Bump extern/qfr from ca6da01 to 76dfda6

Bumps [extern/qfr](https://github.com/cda-tum/qfr) from `ca6da01` to `76dfda6`.
- [Release notes](https://github.com/cda-tum/qfr/releases)
- [Commits](munich-quantum-toolkit/core@ca6da01...76dfda6)

---
updated-dependencies:
- dependency-name: extern/qfr
  dependency-type: direct:production
...

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

Author: dependabot[bot]