fix(deps): adjust dependencies required for grails 7

[jamesfredley]

These changes are currently required to start a grails 7 web project.

The graal-sdk dependency will be handled as follows: bertramdev/asset-pipeline#352 (comment)

After removing the asset-pipeline Gradle plugin from buildSrc/build.gradle and setting.gradle and defining it in one location build.gradle, the graal-sdk dependency is no longer needed.

plugins {
     id "com.bertramlabs.asset-pipeline" version "5.0.1"
}

The larger consolidation of buildSrc, settings.gradle and build.gradle will occur on #347

[codeconsole]

I don't need that dependency to start?

new changes pushed

[codeconsole]

I am not sure grails-plugin-sitemesh3 should be added as a dependency. It should be resolved as a transitive of another dependency

[jamesfredley]

Once that is in place, we will remove it here.

7.0.0-SNAPSHOT is currently an option on start.grails.org and this enables the generated application to start, for now.

[codeconsole]

#399