Swift W3C Trace Context 1.0.0 Beta 4

What's Changed

• Bump actions/checkout from 4.1.7 to 4.2.0 by @dependabot in #21
• Bump codecov/codecov-action from 4 to 5 by @dependabot in #27
• Bump actions/checkout from 4.2.0 to 4.2.2 by @dependabot in #25
• Bump actions/cache from 4.0.2 to 4.1.2 by @dependabot in #26
• Update license headers to reflect move to swift-otel org by @slashmo in #29
• Add Codecov badge to README by @slashmo in #30
• Bump actions/cache from 4.1.2 to 4.2.0 by @dependabot in #28

Full Changelog: 1.0.0-beta.3...1.0.0-beta.4