Release 5.9.0

What's Changed

• fix: perform release workflow by @Johannes-Schneider in #410
• docs: Add Blog Post Series on OSS Process by @MatKuhr in #376
• chore: [DevOps] bump the production-minor-patch group across 1 directory with 8 updates by @dependabot in #416
• chore: [DevOps] bump net.bytebuddy:byte-buddy from 1.14.13 to 1.14.14 in the test group by @dependabot in #414
• refactor: Dependabot Auto Merge GH Workflow by @Johannes-Schneider in #417
• feat: Cron Workflow to Update Maven Dependency Cache by @Johannes-Schneider in #418
• feat: OAuth2Property Supplier for XSUAA Itself by @Johannes-Schneider in #413
• chore: [Destinations] Improve Header Provider Error Handling by @MatKuhr in #419
• feat: [Destinations] Support OAuth2 Refresh Token Authentication Type by @MatKuhr in #404
• fix: Derive current Principal from Basic Authentication Header by @Johannes-Schneider in #420
• chore: [DevOps] bump the test group with 5 updates by @dependabot in #423
• chore: [DevOps] bump the production-minor-patch group across 1 directory with 6 updates by @dependabot in #424
• chore: [DevOps] bump the plugins group across 1 directory with 7 updates by @dependabot in #421
• chore: [DevOps] bump the production-minor-patch group with 3 updates by @dependabot in #426
• chore: [DevOps] bump net.bytebuddy:byte-buddy from 1.14.14 to 1.14.15 in the test group by @dependabot in #431
• chore: [DevOps] bump the production-minor-patch group with 3 updates by @dependabot in #430
• fix: AuthToken Regression by @Johannes-Schneider in #433

Full Changelog: rel/5.8.0...rel/5.9.0