Steps needed to prepare a new release

First PR for new release

Create a new release branch
Checkout the release tags for QuantLib and QuantLib-SWIG for the git submodules in the folder external
Update the version in README.md
Update the environment variable QUANTLIB_VERSION from SNAPSHOT to the new release tag for the .github/workflows/build_maven_artefact.yml workflow
Update the cmake project version
Merge Pull Request

Update the repository

Prepare a new release
Close the associated milestone
Add a new milestone for the next release

Second PR to dump to next `SNAPSHOT` version

Update the environment variable QUANTLIB_VERSION from the new release tag to the next SNAPSHOT release in .github/workflows/build_maven_artefact.yml
Merge Pull Request