43/misc/release strategy (#44)

* pyproject.toml: Lower version bounds

* Renovate: Update default python in CI

* Setup matrix tests

* Update maintainers docs

* Simplify renovate workflow

* Updated maintainer docs

* Dependency upgrade reminders

* Remove old SBOM workflow

* Partially automated release workflow

* Require signed tags

* renovate.json5: Copilot findings

* pyproject.toml: Python <4

* setup-ci-environment: Don't recreate lock file

* run-tests-full.yaml: Copilot findings

Signed-off-by: Dennis Schulmeister-Zimolong <dennis@patk.org>

* Running nox tests in isolation

* GH Actions: Reenable caching, let nox install runtime deps

Signed-off-by: Dennis Schulmeister-Zimolong <dennis@patk.org>

* Let nox install runtime deps, II

* Install all deps for coverage check

* CI Release: Fix python shell not available

* Renovate: Handle python version via draft-PR

Signed-off-by: Dennis Schulmeister-Zimolong <dennis@patk.org>

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Signed-off-by: Dennis Schulmeister-Zimolong <dennis@patk.org>