Bump MSRV to 1.78 for cargo-platform

Author: cecton

Cargo.toml

@@ -7,7 +7,7 @@ description = "Customizable subcommands to build your Wasm projects using xtask.
 homepage = "https://github.com/rustminded/xtask-wasm"
 repository = "https://github.com/rustminded/xtask-wasm"
 documentation = "https://docs.rs/xtask-wasm"
-rust-version = "1.76"
+rust-version = "1.78"
 readme = "README.md"
 categories = ["development-tools::build-utils"]
 keywords = ["wasm", "cli"]