Bump postcss-preset-env from 6.7.0 to 9.1.2 in /services/idp

Bumps [postcss-preset-env](https://github.com/csstools/postcss-plugins/tree/HEAD/plugin-packs/postcss-preset-env) from 6.7.0 to 9.1.2.
- [Changelog](https://github.com/csstools/postcss-plugins/blob/main/plugin-packs/postcss-preset-env/CHANGELOG.md)
- [Commits](https://github.com/csstools/postcss-plugins/commits/HEAD/plugin-packs/postcss-preset-env)

---
updated-dependencies:
- dependency-name: postcss-preset-env
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

services/idp/package.json

@@ -141,7 +141,7 @@
     "postcss-flexbugs-fixes": "4.2.1",
     "postcss-loader": "4.3.0",
     "postcss-normalize": "10.0.1",
-    "postcss-preset-env": "6.7.0",
+    "postcss-preset-env": "9.1.2",
     "postcss-safe-parser": "5.0.2",
     "react-dev-utils": "^11.0.3",
     "resolve": "1.18.1",