Upgrade org.apache.maven:maven-plugin-api 3.6.3 -> 3.8.6

[Picnic-Bot]

This PR contains the following updates:

Package	Type	Update	Change
org.apache.maven:maven-plugin-api (source)	compile	minor	3.6.3 -> 3.8.6

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[Picnic-Bot]

Suggested commit message:

Upgrade Maven API 3.6.3 -> 3.8.6

See:
- https://github.com/apache/maven/releases/tag/maven-3.8.5
- https://github.com/apache/maven/releases/tag/maven-3.8.6
- https://github.com/apache/maven/compare/maven-3.8.4...maven-3.8.6

[rickie]

Suggested commit message:

Upgrade Maven API 3.6.3 -> 3.8.6 (#184)

See:
- https://maven.apache.org/release-notes-all.html
- https://github.com/apache/maven/releases/tag/maven-3.8.4
- https://github.com/apache/maven/releases/tag/maven-3.8.5
- https://github.com/apache/maven/releases/tag/maven-3.8.6
- https://github.com/apache/maven/compare/maven-3.6.3...maven-3.8.6

[rickie]

@Stephan202 see suggested commit message 🔝.

[Stephan202]

Tweaked it (fixed the diff URL, linked only to published Github releases). Will merge! 🚀