chore: unreleased changes

[stainless-bot]

This PR contains commits from the following PRs:

• chore(internal): add overloads to client.get for streaming #19
• docs: point to github repo instead of email contact #18
• ci: update release config #17
• chore(internal): improve internal test helper #16
• fix(types): correct items type for individuals arg in enroll_many #15
• chore(internal): restructure core streaming implementation #14
• chore(internal): add empty request preparation method #13
• chore(internal): minor formatting change #12
• fix(sse): small improvement to handling server-sent events #11
• chore(internal): update lock file #10
• chore(internal): add tests for base url handling #9
• chore(internal): fix workflow comment url #8
• chore(internal): fix bug with transform utility & key aliases #7
• chore(internal): update changelog config #5

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After merging this PR, if there are any user facing changes, another PR will be created with the changelog & version bump.