feat: use cpio crate for initramfs creation

Add the `cpio` crate as dependency, removing e2fsprogs external dependency.

Cargo.lock

@@ -243,6 +243,12 @@ version = "0.8.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
 
+[[package]]
+name = "cpio"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "938e716cb1ade5d6c8f959c13a7248b889c07491fc7e41167c3afe20f8f0de1e"
+
 [[package]]
 name = "crc32fast"
 version = "1.5.0"
@@ -296,6 +302,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "clap",
+ "cpio",
  "dirs",
  "flate2",
  "futures-util",