Bump ppft from 1.7.6.7 to 1.7.6.8

Bumps [ppft](https://github.com/uqfoundation/ppft) from 1.7.6.7 to 1.7.6.8.
- [Release notes](https://github.com/uqfoundation/ppft/releases)
- [Changelog](https://github.com/uqfoundation/ppft/blob/master/CHANGELOG)
- [Commits](uqfoundation/ppft@ppft-1.7.6.7...1.7.6.8)

---
updated-dependencies:
- dependency-name: ppft
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.txt

@@ -70,7 +70,7 @@ plotly==5.18.0
     # via pymatgen
 pox==0.3.3
     # via pathos
-ppft==1.7.6.7
+ppft==1.7.6.8
     # via pathos
 pybtex==0.24.0
     # via pymatgen