Paul wanted a Makefile target that:
- takes the target version as an argument (V=1.0.7-rc1),
- creates a release/<V> branch from main,
- runs 'dotnet-gitversion /updateprojectfiles' to bump
  <Version> across all .csproj from git history,
- commits the bump on the release branch (not on main, so
  main stays clean),
- pushes the new branch to origin.

The /src/**/*.csproj paths and CHANGELOG.md are excluded from
Forgejo's protected-branch rule so the bump commit goes
through on the release branch.

The target refuses to run unless the operator is already on
main with a clean working tree — no automatic checkout to
main, so the bump never lands on the wrong branch by
accident.

The version in the branch name (V=...) is an intent label.
The version GitVersion writes into the .csproj is whatever
GitVersion computes from git history (last tag + commit
count), so assembly versions stay truthful even when the
branch name is aspirational.

chore(release): bump version via gitversion for 1.0.7-rc1 15f018117f