build(deps): bump prisma from 5.20.0 to 5.21.0 in /backend

Bumps [prisma](https://github.com/prisma/prisma/tree/HEAD/packages/cli) from 5.20.0 to 5.21.0.
- [Release notes](https://github.com/prisma/prisma/releases)
- [Commits](https://github.com/prisma/prisma/commits/5.21.0/packages/cli)

---
updated-dependencies:
- dependency-name: prisma
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/package.json

@@ -47,7 +47,7 @@
     "graphql-yoga": "^5.7.0",
     "jose": "^5.9.4",
     "nanoid": "^3.3.7",
-    "prisma": "^5.20.0",
+    "prisma": "^5.21.0",
     "prisma-extension-soft-delete": "^1.0.1",
     "reflect-metadata": "^0.2.2",
     "tsconfig-paths": "^4.2.0",