Bump docs-resources from ff1e5eb to c90c0bf

Bumps [docs-resources](https://github.com/riscv/docs-resources) from `ff1e5eb` to `c90c0bf`.
- [Commits](riscv/docs-resources@ff1e5eb...c90c0bf)

---
updated-dependencies:
- dependency-name: docs-resources
  dependency-version: c90c0bfe69d15c977458788f511215fb75745011
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]