Render end_of_line type hints without preceding colon

rust-analyzer.inlayHints.typeHints.location was added in #21322, the value "end_of_line" leads to the type hint being rendered at the end, including the initial colon unless rust-analyzer.inlayHints.renderColons is set to false. Example: https://github.com/rust-lang/rust-analyzer/issues/4318#issuecomment-3678112247

It would be great if there was a way to disable the colons just for the inlay hints at the end of the line, so you don't have to disable all colons if you don't like the ones for the end_of_line case.

Some users might prefer to have the colon be there (for example to avoid the hint looking like a method chaining hint), so I guess the current behaviour could be kept available or even as default.

Has been mentioned previously:

Maybe it will be kind of weird if the inlay hint is put at the end of the line and still started with ":", I think the text should also be modified with the change of placing way

Originally posted by @Decodetalkers in https://github.com/rust-lang/rust-analyzer/pull/21322#discussion_r3013133281

Start with the configuration documentation for rust-analyzer.inlayHints.typeHints.location and rust-analyzer.inlayHints.renderColons, then inspect the implementation introduced in #21322. Done means end_of_line type hints can control their preceding colon independently while the existing colon behavior remains available.