Ignore doctest for non-exported macro

Rust 1.62 introduced a breaking change where doctests for non-exported
macros are now run by default. These don't compile because the macro
can't be imported in it.
See rust-lang/rust#97030 for more info.

Author: jjant

aws/rust-runtime/aws-types/src/build_metadata.rs

@@ -41,7 +41,7 @@ pub enum OsFamily {
 /// is set to a specific value. This macro simplifies checking the current OS family.
 ///
 /// Usage:
-/// ```rust
+/// ```ignore
 /// let os = get_os_family!(target_os: ("linux", OsFamily::Windows), ("android", OsFamily::Android));
 /// ```
 macro_rules! get_os_family {