chore: Update Code of Conduct to Redirect to CNCF CoC (#9104)

CODE_OF_CONDUCT.md

-k3s observes the [CNCF Community Code of Conduct](https://github.com/cncf/foundation/blob/master/code-of-conduct.md), reproduced below for emphasis.
-
-### Contributor Code of Conduct
-
-As contributors and maintainers of this project, and in the interest of fostering
-an open and welcoming community, we pledge to respect all people who contribute
-through reporting issues, posting feature requests, updating documentation,
-submitting pull requests or patches, and other activities.
-
-We are committed to making participation in this project a harassment-free experience for
-everyone, regardless of level of experience, gender, gender identity and expression,
-sexual orientation, disability, personal appearance, body size, race, ethnicity, age,
-religion, or nationality.
-
-Examples of unacceptable behavior by participants include:
-
-* The use of sexualized language or imagery
-* Personal attacks
-* Trolling or insulting/derogatory comments
-* Public or private harassment
-* Publishing others' private information, such as physical or electronic addresses,
- without explicit permission
-* Other unethical or unprofessional conduct.
-
-Project maintainers have the right and responsibility to remove, edit, or reject
-comments, commits, code, wiki edits, issues, and other contributions that are not
-aligned to this Code of Conduct. By adopting this Code of Conduct, project maintainers
-commit themselves to fairly and consistently applying these principles to every aspect
-of managing this project. Project maintainers who do not follow or enforce the Code of
-Conduct may be permanently removed from the project team.
-
-This code of conduct applies both within project spaces and in public spaces
-when an individual is representing the project or its community.
-
-Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting a Rancher administrator  on [Slack](https://slack.rancher.io), or <conduct@suse.com>.
-
-This Code of Conduct is adapted from the Contributor Covenant
-(http://contributor-covenant.org), version 1.2.0, available at
-http://contributor-covenant.org/version/1/2/0/
+# Community Code of Conduct
+k3s observes the [CNCF Community Code of Conduct](https://github.com/cncf/foundation/blob/main/code-of-conduct.md).
 
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting a Rancher administrator on [Slack](https://slack.rancher.io), or <conduct@suse.com>.