style: apply nightly rustfmt import grouping across the workspace

rustfmt.toml sets group_imports, imports_granularity and imports_layout,
which are nightly-only; agents formatted with stable rustfmt, which
ignored them. This is a formatting-only pass with `cargo +nightly fmt`.

Test Plan:
- cargo clippy --workspace --all-targets -- -D warnings
- cargo test --workspace

crates/ghostty-font/src/shaper/noop.rs

@@ -2,8 +2,10 @@
 //! Each individual codepoint is mapped directly to the detected text run
 //! font's glyph index.
 
-use crate::face::freetype::Face;
-use crate::shape::{self, Cell};
+use crate::{
+    face::freetype::Face,
+    shape::{self, Cell},
+};
 
 #[derive(Debug, Clone, Copy)]
 struct Codepoint {