Bump serilog dependencies to v9 (major)

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
Serilog.Extensions.Hosting	8.0.0 -> 9.0.0
Serilog.Settings.Configuration	8.0.4 -> 9.0.0

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Release Notes

serilog/serilog-extensions-hosting (Serilog.Extensions.Hosting)

v9.0.0

What's Changed

• #​96 - update to .NET 9 SDK, Microsoft.Extensions.Hosting 9.0.0, Serilog 4.2.0 (@​nblumhardt)
• #​85, #​86 - whitespace formatting, file-scoped namespaces (@​sungam3r)
• #​87 - update samples and README to use newer .NET hosting APIs (@​nblumhardt)

serilog/serilog-settings-configuration (Serilog.Settings.Configuration)

v9.0.0

What's Changed

• #​414, #​446 - code clean-up and solution improvements (@​sungam3r)
• #​444, #​445 - update to .NET 9 SDK and Microsoft.Extensions.Configuration 9.0.0 (@​nblumhardt)

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Configuration

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