Update eframe requirement from 0.22.0 to 0.26.2 in /serial_term

Updates the requirements on [eframe](https://github.com/emilk/egui) to permit the latest version.
- [Release notes](https://github.com/emilk/egui/releases)
- [Changelog](https://github.com/emilk/egui/blob/master/CHANGELOG.md)
- [Commits](emilk/egui@0.22.0...0.26.2)

---
updated-dependencies:
- dependency-name: eframe
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

serial_term/Cargo.toml

@@ -6,6 +6,6 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-eframe = "0.22.0"
+eframe = "0.26.2"
 egui = "0.21.0"
 serialport = "4.2.0"