Munge pre-release versions in Vanagon builds

[Sharpie]

Short description

PR OpenVoxProject/vanagon#95 updated Vanagon's handling of Git tags. If the tag matches a semver.org pre-release with "alpha", "beta" or "rc" as the pre-release identifier, then the "-" in the version string is substituted for "~". That is, a tag like 9.0.0-beta1 becomes the following package version: 9.0.0~beta1

This is done because the dpkg and rpm package managers treat ~ specially and sort any version strings containing it before all other strings. This changes allows a 9.0.0~alpha1 package to upgrade to 9.0.0~beta1, and then to 9.0.0~rc0, and finally to 9.0.0.

This commit updates the munging logic in the build_vanagon.yml workflow to correctly pass these versions to rake vox:upload.

See: https://semver.org
See: https://manpages.debian.org/bookworm/dpkg-dev/deb-version.7.en.html#Sorting_algorithm
See: https://rpm.org/docs/6.0.x/man/rpm-version.7#Comparing

Checklist

I have:

• read the CONTRIBUTING.md document
• read and accepted the Developer Certificate of Origin document and added a Signed-off-by annotation to each of my commits
• read and accepted the AI Policy document and added Generated-by or Assisted-by annotations to each of my commits created with the help of an AI agent
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)