Move approver to maintainer for Cosign

[haydentherapper]

I'd like to propose myself as a maintainer of Cosign.

I am currently an approver on Cosign and have been active in reviews since beginning development on Cosign. I'm one of the top contributors for the repo. As per the contributor requirements, I've merged at least 30 PRs (59). I have significant expertise in the signing and verification code, having added multiple features (1, 2, 3) and worked on verification bug/vuln fixes. I've been the SME on PKI changes and improvements also.

Summary

Release Note

Documentation

[haydentherapper]

cc'ing current maintainers for +1s: @Dentrax @dekkagaijin @developer-guy @hectorj2f @mattmoor @znewman01

cc @bobcallaway @priyawadhwa for approval and merge once there's +1s

[github-actions]

🍹 preview on sigstore/github-prod

Pulumi report

Previewing update (sigstore/github-prod)

View Live: https://app.pulumi.com/sigstore/sigstore-github-sync/github-prod/previews/bd970b77-d385-4c00-964c-dd27d0ae25bd

@ Previewing update.....
pulumi:pulumi:Stack: (same)
[urn=urn:pulumi:github-prod::sigstore-github-sync::pulumi:pulumi:Stack::sigstore-github-sync-github-prod]
+ github:index/teamMembership:TeamMembership: (create)
    [urn=urn:pulumi:github-prod::sigstore-github-sync::github:index/teamMembership:TeamMembership::haydentherapper-cosign-codeowners]
    role      : "member"
    teamId    : "4722092"
    username  : "haydentherapper"
@ Previewing update....
- github:index/repositoryCollaborator:RepositoryCollaborator: (delete)
    [id=cosign:haydentherapper]
    [urn=urn:pulumi:github-prod::sigstore-github-sync::github:index/repositoryCollaborator:RepositoryCollaborator::cosign-haydentherapper]
    permission               : "push"
    permissionDiffSuppression: false
    repository               : "cosign"
    username                 : "haydentherapper"
Resources:
+ 1 to create
- 1 to delete
2 changes. 515 unchanged