Update stabilization to 1.89

Author: ehuss

src/cargo/core/features.rs

@@ -1276,7 +1276,7 @@ impl CliUnstable {
             "codegen-backend" => self.codegen_backend = parse_empty(k, v)?,
             "config-include" => self.config_include = parse_empty(k, v)?,
             "direct-minimal-versions" => self.direct_minimal_versions = parse_empty(k, v)?,
-            "doctest-xcompile" => stabilized_warn(k, "1.88", STABILIZED_DOCTEST_XCOMPILE),
+            "doctest-xcompile" => stabilized_warn(k, "1.89", STABILIZED_DOCTEST_XCOMPILE),
             "dual-proc-macros" => self.dual_proc_macros = parse_empty(k, v)?,
             "feature-unification" => self.feature_unification = parse_empty(k, v)?,
             "gc" => self.gc = parse_empty(k, v)?,

src/doc/src/reference/unstable.md

@@ -2158,4 +2158,4 @@ More information can be found in the [config chapter](config.md#cache).
 
 ## doctest-xcompile
 
-Doctest cross-compiling is now unconditionally enabled starting in Rust 1.88. Running doctests with `cargo test` will now honor the `--target` flag.
+Doctest cross-compiling is now unconditionally enabled starting in Rust 1.89. Running doctests with `cargo test` will now honor the `--target` flag.