William Caban stepping down as maintainer and from teams

[scottrigby]

closes #190

• William Caban stepping down as OpenGitOps project maintainer
• William for now leaving OpenGitOps team focusing on GitOps impact on environmental sustainability
• William for now leaving OpenGitOps team focusing on machine learning relationship to GitOps

follow-up:

• remove William invite from project meeting Google calendar events (both 1st and 3rd week recurring events)
• move @williamcaban to @open-gitops/alumni team, and remove from all other teams
• remove william from #opengitops-maintainers CNCF Slack channel
• remove William from maintainers mailing list (cncf-opengitops-maintainers@lists.cncf.io) – opened service desk ticket https://cncfservicedesk.atlassian.net/servicedesk/customer/portal/1/CNCFSD-2372?created=true
• request removing William from Service Desk OpenGitOps group – opened service desk ticket https://cncfservicedesk.atlassian.net/servicedesk/customer/portal/1/CNCFSD-2372?created=true

related:

• Create onboarding & offboarding checklists for chairs, maintainers, and team members #176

[williamcaban]

/lgtm