Add :tools lsp checks for +lsp flag

Also:
- Reorganizes some :lang modules' packages.el file.
- Adds setuptools check in lang/python
- Adds javac check in lang/java
- Removes the depends-on! macro

modules/lang/rust/packages.el

@@ -1,8 +1,6 @@
 ;; -*- no-byte-compile: t; -*-
 ;;; lang/rust/packages.el
 
-;; requires rust cargo racer
-
 (package! rust-mode)
 
 (when (featurep! :tools flycheck)