Updates the .editorconfig file, first introduced in 2021
(see PR #21123, commit 7a135d57) w.r.t. following changes:
- consider Rust .rs files (relevant since #28076, commit bbbbdb0c)
- reflect build system change to CMake (#30454, #30664)
- add setting for the bare Makefile still used for depends builds
Can be tested e.g. by using the editorconfig-vim plugin
(https://github.com/editorconfig/editorconfig-vim).