docs: update README.md and SECURITY.md to reflect passed EOL dates

Signed-off-by: Filip Skokan <panva.ip@gmail.com>

Author: panva

README.md

@@ -245,7 +245,6 @@ The supported JavaScript runtimes include those that support the utilized Web AP
 | Version                                                  | Security Fixes 🔑 | Other Bug Fixes 🐞 | New Features ⭐ | Runtime and Module type         |
 | -------------------------------------------------------- | ----------------- | ------------------ | --------------- | ------------------------------- |
 | [v6.x](https://github.com/panva/openid-client/tree/v6.x) | [Security Policy] | ✅                 | ✅              | Universal[^universal] ESM[^cjs] |
-| [v5.x](https://github.com/panva/openid-client/tree/v5.x) | [Security Policy] | ❌                 | ❌              | Node.js CJS + ESM               |
 
 [sponsor-auth0]: https://a0.to/signup/panva
 [WebCryptoAPI]: https://w3c.github.io/webcrypto/

SECURITY.md

@@ -7,7 +7,6 @@ The following major versions are currently supported with security updates.
 | Version                                                  | End-of-life |
 | -------------------------------------------------------- | ----------- |
 | [v6.x](https://github.com/panva/openid-client/tree/v6.x) | TBD         |
-| [v5.x](https://github.com/panva/openid-client/tree/v5.x) | 2026-04-30  |
 
 End-of-life for the current release will be determined prior to the release of its successor.