deps: update dependency system.collections.immutable to 6.0.1

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
System.Collections.Immutable (source)	6.0.0 -> 6.0.1

---

Release Notes

dotnet/runtime (System.Collections.Immutable)

### [`v6.0.1`](https://redirect.github.com/dotnet/runtime/releases/tag/v6.0.1): .NET 6.0.1 [Release](https://redirect.github.com/dotnet/core/releases/tag/v6.0.1)

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.