Mark json5 as unmaintained

Author: jayvdb

crates/json5/RUSTSEC-0000-0000.md

@@ -0,0 +1,21 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "json5"
+date = "2025-11-16"
+url = "https://github.com/callum-oakley/json5-rs/issues/51"
+informational = "unmaintained"
+
+[versions]
+patched = []
+```
+
+# json5 crate is unmaintained
+
+The `json5` crate is no longer actively maintained.  If you rely on this crate, consider switching to a recommended alternative.
+
+## Recommended alternatives
+
+- [`serde_json5`](https://crates.io/crates/serde_json5)
+- [`jsonc-parser`](https://crates.io/crates/jsonc-parser)
+- [`json=five`](https://crates.io/crates/json-five)