Update release refs

[jamis]

Update release references to the canonical repo and tag.

[Copilot]

Pull Request Overview

This PR updates release references from a personal fork to the canonical mongodb-labs repository and removes outdated configuration. The changes standardize the release workflow to use official versioned actions.

• Updates GitHub Actions references from jamis/drivers-github-tools to mongodb-labs/drivers-github-tools@v3
• Removes the unused SILK_ASSET_GROUP environment variable and corresponding workflow parameter
• Deletes the now-unnecessary .github/release.yml configuration file

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
.github/workflows/release.yml	Updates action references to canonical repo with v3 tag and removes SILK_ASSET_GROUP configuration
.github/release.yml	Removes entire file as it's no longer needed

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