Update Scala template to include `.tasty` files introduced in Scala 3

[KacperFKorban]

Reasons for making this change:

Scala 3 introduced a new type of IR file that is produced when compiling Scala sources with the new compiler - .tasty files. When version control is concerned, those files should be treated the same way .class files are.

My relationship to the project: I'm one of the maintainers see here.

Links to documentation supporting these rule changes:

https://docs.scala-lang.org/scala3/guides/tasty-overview.html

[michaelimasih]

Reasons for making this change:

Scala 3 introduced a new type of IR file that is produced when compiling Scala sources with the new compiler - .tasty files. When version control is concerned, those files should be treated the same way .class files are.

My relationship to the project: I'm one of the maintainers see here.

Links to documentation supporting these rule changes:

https://docs.scala-lang.org/scala3/guides/tasty-overview.html