tooling: release automation

[LukeWinikates]

Releasing a new SDK version has an 18-step process. It seems as though this could be simplified a bit using make recipes, or a possibly using a tool like goreleaser.

[LukeWinikates]

• update RELEASING.md to reflect new steps we're introducing for the OSS license process
• where possible, create make targets for the steps in RELEASING.md
• see if we can make the tagging steps a bit less cumbersome
• look into whether drafting the release using the github UI is the best approach - the auto-generated release notes have been a great starting point for previous release notes
• look into whether letting the github UI create the tag for us is the best approach

[LukeWinikates]

• maybe we can make tool that suggests the next release version string for us

[LukeWinikates]

• maybe we can do something automated with OSM tooling to create a PR to update the open_source_licenses.txt file