Updated community Mission page breaks the build

[chalin]

For the failing build log, see https://github.com/open-telemetry/opentelemetry.io/actions/runs/13903094839/job/38899486360#step:7:1793. Here is an excerpt showing the link-check error:

community/mission/index.html
  target does not exist --- community/mission/index.html --> ./code-of-conduct.md

[chalin]

This is due to the following PR:

• Use relative links community#2507

See https://github.com/open-telemetry/community/pull/2507/files#r1999348673.

/cc @trask