Update dependency Serilog.Sinks.File to v5

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
Serilog.Sinks.File (source)	nuget	major	4.1.0 -> 5.0.0

---

Release Notes

serilog/serilog-sinks-file

### [`v5.0.0`](https://togithub.com/serilog/serilog-sinks-file/releases/v5.0.0) - [#​123](https://togithub.com/serilog/serilog-sinks-file/issues/123) - update sourcelink support ([@​maciejw](https://togithub.com/maciejw)) - [#​166](https://togithub.com/serilog/serilog-sinks-file/issues/166) - support C# 8 nullable reference types; update targets/dependencies (fixing [#​104](https://togithub.com/serilog/serilog-sinks-file/issues/104)) ([@​rafaelsc](https://togithub.com/rafaelsc)) - [#​141](https://togithub.com/serilog/serilog-sinks-file/issues/141) - allow composition of `FileLifecycleHooks` ([@​EamonHetherton](https://togithub.com/EamonHetherton)) - [#​145](https://togithub.com/serilog/serilog-sinks-file/issues/145) - improve docs ([@​cocowalla](https://togithub.com/cocowalla)) - [#​147](https://togithub.com/serilog/serilog-sinks-file/issues/147) - fix validation of `fileSizeLimit` ([@​cocowalla](https://togithub.com/cocowalla)) - [#​167](https://togithub.com/serilog/serilog-sinks-file/issues/167) - improve XDOCs ([@​rafaelsc](https://togithub.com/rafaelsc)) - [#​190](https://togithub.com/serilog/serilog-sinks-file/issues/190) - packaging updates ([@​augustoproiete](https://togithub.com/augustoproiete)) - [#​189](https://togithub.com/serilog/serilog-sinks-file/issues/189) - allow `FileLifecycleHooks` to observe opened filename ([@​augustoproiete](https://togithub.com/augustoproiete)) - [#​196](https://togithub.com/serilog/serilog-sinks-file/issues/196) - log to `SelLog` when path rolling fails ([@​pvandervelde](https://togithub.com/pvandervelde)) - [#​222](https://togithub.com/serilog/serilog-sinks-file/issues/222) - remove unnecessary dependencies ([@​bdovaz](https://togithub.com/bdovaz)) - [#​227](https://togithub.com/serilog/serilog-sinks-file/issues/227) - unpin the assembly version ([@​nblumhardt](https://togithub.com/nblumhardt)) - [#​210](https://togithub.com/serilog/serilog-sinks-file/issues/210) - allow `FileLifecycleHooks` to (attempt to) set the underlying stream's length ([@​augustoproiete](https://togithub.com/augustoproiete))

---

Configuration

📅 Schedule: At any time (no schedule defined).

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

♻ Rebasing: Whenever PR becomes conflicted, 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, click this checkbox.

---

This PR has been generated by WhiteSource Renovate. View repository job log here.