[gradle] JReleaser project and gradle project variables clash

[crschnick]

If you try to reference the gradle project within the jreleaser scope, it always refers to the jreleaser.project by default. This can lead to bugs if you're trying to access gradle project properties.

[aalmiray]

Indeed. This is true for every JReleaser DSL element whose name shadows and existing Gradle model DSL.

Current workaround: define a script variable pointing to Gradle's project under a different name, or the actual target property i.e, def projectName = project.name. This definition must be performed outside of the jreleaser extension block.

Consider choosing a different name for 2.x taking into account that core DSL might need an update as well.

Add a note to https://github.com/jreleaser/jreleaser.github.io/blob/main/docs/modules/tools/pages/jreleaser-gradle.adoc regarding this name clash and how to workardound it.