* Use Java 17 for building MapStruct (still Java 8 compatible)
* Upgrade to Spring 6 for tests
* Adjust excludes and min tests version for some integration tests
Prior to this MapStruct would only use `Elements#getTypeElement`.
With this PR if the mapper being generated is within a module MapStruct will use that module
for the methods that are needed (getTypeElement and getPackageElement).
Adapt the build to require a minimum Java 11 for building the processor module.
Adapt the GitHub actions to properly run integration tests with Java 8
Ignore Java 9 usages for the animal-sniffer-plugin
Update GitHub Actions for tests to run on Java 11, 13, 16 and 17-ea.
Update Lombok so tests can run on 16+
Add jaxb-runtime dependency to the maven-jaxb2-plugin see https://github.com/highsource/maven-jaxb2-plugin/issues/148
Disable cdi integration test on Java 16+ until we find a solution for them
Upgrades:
* Maven Enforcer Plugin to 3.0.0-M3
* Maven Surefire Plugin to 3.0.0-M5
* Maven Checkstyle Plugin to 3.1.1
* Maven Bundle Plugin to 5.1.1
* Jacoco Maven Plugin to 0.8.6
* Checkstyle to 8.36.1
* JUnit Jipiter to 5.7.0
* AssertJ to 3.17.2
* Guava to 29.0-jre
Fix AssertJ breaking changes
Use Java 8 or Apache Commons IO instead of Guava where possible
Update GitHub Actions to use JDK 14 and JDK 15-ea
