Fixes: https://github.com/spring-projects/spring-retry/issues/480
* Add `flatten-maven-plugin` to resolve properties
and remove unnecessary build info from the final POM of the artifact to install/deploy
* Revert `version` extraction from POM via `sed` command in the build action
* Remove `flatten.clean` from the Maven Flatter Plugin, since `.flattened-pom.xml` generated file is landed in the `/target` dir
* Add `pomElements/profiles` for removal in the result `.flattened-pom.xml`
Since there is no `revision` property in POM, we cannot use `sed` command to extract project version from the POM.
* Use more Maven-friendly `mvn help:evaluate -Dexpression="project.version" -q -DforceStdout` command to get the current project version
* Remove tentative `finish_release_tmp.yml` since `actions\build` has been fixed now
Fixes: https://github.com/spring-projects/spring-retry/issues/476
* Add `maven-assembly-plugin` to Zip Javadocs from the `apidocs` dir into a `*-docs.zip` artifact
* Modify `build-and-deploy-snapshot.yml` and `release.yml` to assign `zip.deployed=false` attribute to Zip artifacts
* Also mark `docs.zip` files as `zip.type=docs`
