Fix toBuilder generator with generics

[rdesgroppes]

This is meant to resolve #1459 as follows:

   /**
    * Creates a builder for {@link ImmutableToBuilderClassicWithGenerics ImmutableToBuilderClassicWithGenerics}.prefilled
    * with attibute values of {@code this} instance to easily create modified copies.
    * @return A new ImmutableToBuilderClassicWithGenerics builder with attributes of {@code this} instance
    */
-  public ImmutableToBuilderClassicWithGenerics.Builder<T><T> toBuilder()
+  public ImmutableToBuilderClassicWithGenerics.Builder<T> toBuilder() {
     return ImmutableToBuilderClassicWithGenerics.<T>builder().from(this);
   }

(snippet comes from value-fixture/target/generated-sources/annotations/org/immutables/fixture/builder/ImmutableToBuilderClassicWithGenerics.java)

[rdesgroppes]

@elucash questions I asked myself while working on this:

1. is the remaining [type.typeBuilder.relative] fine? I don't see it used as return type for other builder method signatures...
2. should I augment the existing ToBuilderMethod interface with a new entry point instead of creating an ad-hoc one? (ToBuilderClassicWithGenerics)

Thanks!

[elucash]

Yes, the change appears to be correct. typeBuilder and other similar accessors return an object with generic type parameters applied, it's the .typeBuilder.relativeRaw would leave generics out. Thank you for the PR!

[rdesgroppes]

Thanks again, @elucash. May we expect a release in the near future?

[elucash]

Should release soon, currently evaluating jakarta.* related change/configuration, which will also go into release. I dunno, about a week