Make assemble depend on shadowJar even if it is added later

[Jonathing]

Currently, Shadow makes the assemble task depend on shadowJar if and only if it exists when the shadow plugin is applied. This is usually fine, but in the case of some unorthodox setups, it can mean that if the Shadow plugin is applied before the base plugin, the assemble task can end up existing without depending on the shadowJar task.

To address this, instead of using TaskContainer#findByName(String), we can use #named(Spec<String>) to work with a live view of the container. This is very similar to how #withType(Class<S extends T> works, where configureEach applies the action to each member that passes the spec, even if it is added later.

The only thing I don't know what to do now with this PR is how to write tests for it. I'd appreciate your help with that. Thanks!

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For the record, you can easily test this using this snippet. Apologies for the Groovy DSL 😛

println "findByName testTask2 = ${tasks.findByName('testTask2')}"
tasks.named ({ 'testTask2'.equals(it) } as Spec<String>).configureEach {
    println "named(spec) testTask2 = $it"
}

println 'Registering testTask2'
tasks.register('testTask2')

println "findByName testTask2 = ${tasks.findByName('testTask2')}"
tasks.named ({ 'testTask2'.equals(it) } as Spec<String>).configureEach {
    println "named(spec) testTask2 = $it"
}

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• CHANGELOG's "Unreleased" section has been updated, if applicable.

[Goooler]

The only thing I don't know what to do now with this PR is how to write tests for it. I'd appreciate your help with that.

I tried in #1768, but it can't work against this.

It works now.

[Goooler]

This looks could be moved into the upper block.

[Goooler]

We can't. TaskProvider should be passed into dependsOn. See #1768.