Rust Dependency: Update mu_pi requirement from 6 to 7

Updates the requirements on [mu_pi](https://github.com/microsoft/mu_rust_pi) to permit the latest version.
- [Release notes](https://github.com/microsoft/mu_rust_pi/releases)
- [Commits](microsoft/mu_rust_pi@v6.0.0...v7.0.0)

---
updated-dependencies:
- dependency-name: mu_pi
  dependency-version: 7.0.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Cargo.toml

@@ -15,7 +15,7 @@ members = [
 HidIo = { path = "HidPkg/Crates/HidIo" }
 hidparser = { version = "1" }
 HiiKeyboardLayout = { path = "HidPkg/Crates/HiiKeyboardLayout" }
-mu_pi = { version = "6" }
+mu_pi = { version = "7" }
 mu_rust_helpers = { version = "3" }
 MuTelemetryHelperLib = { path = "MsWheaPkg/Crates/MuTelemetryHelperLib" }
 RustAdvancedLoggerDxe = { path = "AdvLoggerPkg/Crates/RustAdvancedLoggerDxe" }