macros: Drop anyhow dependency

It is used in a single place and it is easy to remove, so it doesn't
seem
worth it to keep depending on it.

gtk4-macros/Cargo.toml

@@ -21,7 +21,6 @@ xml_validation = ["quick-xml"]
 blueprint = []
 
 [dependencies]
-anyhow = "1.0"
 quick-xml = {version = "0.31", optional = true}
 proc-macro-crate = "3.0"
 proc-macro2 = "1.0"

gtk4-macros/src/blueprint.rs

@@ -1,12 +1,10 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
 use std::{
-    io::{Read, Write},
+    io::{Error, ErrorKind, Read, Result, Write},
     process::{Command, Stdio},
 };
 
-use anyhow::{bail, Result};
-
 pub(crate) fn compile_blueprint(blueprint: &[u8]) -> Result<String> {
     let mut compiler = Command::new("blueprint-compiler")
         .args(["compile", "-"])
@@ -24,7 +22,7 @@ pub(crate) fn compile_blueprint(blueprint: &[u8]) -> Result<String> {
     compiler.stdout.unwrap().read_to_string(&mut buf)?;
 
     if !buf.starts_with('<') {
-        bail!(buf);
+        return Err(Error::new(ErrorKind::Other, buf));
     }
 
     Ok(buf)