Update nix dependency (serialport#75)

* Upgrade nix to 0.26

Remove the patch version in the dependency definition to get minor fixes
automatically. This shouldn't be a problem as nix should be API stable
across patch versions.

Signed-off-by: Richard Leitner <richard.leitner@skidata.com>

* Raise the MSRV to 1.56.1

This is needed as nix v0.26.0 raised its MSRV to 1.56.1. For more
information please see the changelog:
	https://github.com/nix-rust/nix/blob/master/CHANGELOG.md#0260---2022-11-29

Or the corresponding PR:
	nix-rust/nix#1792

Signed-off-by: Richard Leitner <richard.leitner@skidata.com>

Signed-off-by: Richard Leitner <richard.leitner@skidata.com>

.github/workflows/ci.yaml

@@ -56,7 +56,7 @@ jobs:
       disable_tests: true
       extra_packages: libudev-dev
       target: x86_64-unknown-linux-gnu
-      toolchain: "1.46.0"
+      toolchain: "1.56.1"
 
   # --------------------------------------------------------------------------
   # BUILD

Cargo.toml

@@ -17,7 +17,7 @@ categories = ["hardware-support"]
 [target."cfg(unix)".dependencies]
 bitflags = "1.3.2"
 cfg-if = "1.0.0"
-nix = { version = "0.25.0", default-features = false, features = ["fs", "ioctl", "poll", "signal", "term"] }
+nix = { version = "0.26", default-features = false, features = ["fs", "ioctl", "poll", "signal", "term"] }
 
 [target.'cfg(all(target_os = "linux", not(target_env = "musl")))'.dependencies]
 libudev = { version = "0.3.0", optional = true }

README.md

@@ -100,7 +100,7 @@ can help debug software or hardware errors.
 
 # Dependencies
 
-Rust versions 1.46.0 and higher are supported.
+Rust versions 1.56.1 and higher are supported.
 
 For GNU Linux `pkg-config` headers are required: