Move Checksum Generation to Composite

[BowTiedDevOps]

The action used to generate a checksum for the github release flow (https://github.com/stacks-network/stacks-core/blob/develop/.github/workflows/github-release.yml#L59-L67) had to be updated to a newer version due to an error causing the step to fail. After this issue arose, a quick fix in order to make the action work was merging a PR to the master branch (https://github.com/stacks-network/stacks-core/pull/4374).

The goal of this PR is to move the generation of checksums to composite actions for easier fixes if they are necessary, and do it with bash instead of a predefined action for consistency and significantly lower chances of unexpected failures.

This PR should be merged after the one in actions repository is: https://github.com/stacks-network/actions/pull/24

Reference issue: https://github.com/stacks-network/stacks-core/issues/4375 Reference action run: https://github.com/BowTiedDevOps/stacks-core/actions/runs/7920897073/job/21625430204#step:3:57