Housekeeping: replace repo-level CODE_OF_CONDUCT

apple/servicetalk#3658 mergeddocs-only

What it touches

docs: 1

Modules: CODE_OF_CONDUCT.adoc (1)

Architectural impact (arcade-agent diff_impact)

No production Java file of this PR maps into the dependency graph (tests, build, CI or docs only). Tests are excluded from the graph by design.

Files