Add Update-DotnetVersion script

Updates donet SDK and Runtime versions together

Allows for
.\Scripts\Update-DotnetVersion.ps1
OR
.\Scripts\Update-DotnetVersion.ps1 7.0

scripts/Update-DotnetVersion.ps1

@@ -0,0 +1,35 @@
+param ( [string]$version = "6.0")
+
+$encoding = [System.Text.UTF8Encoding]::new($false)
+
+$path = Split-Path $MyInvocation.MyCommand.Path -Parent
+$uri = "https://raw.githubusercontent.com/dotnet/core/main/release-notes/$version/releases.json"
+
+# Get .NET version info
+$releaseJson = Invoke-WebRequest -Uri $uri -ContentType "application/json" -Method Get -UseBasicParsing
+$versionResult = $releaseJson.Content | Out-String | ConvertFrom-Json 
+Write-Output "Dotnet version info"
+$versionResult | Format-List -Property channel-version, latest-release, latest-release-date, latest-runtime, latest-sdk, support-phase, eol-date
+
+# Update global.json file
+$globalJson = [System.IO.Path]::Combine($path, "..\global.json")
+$globalJson = Resolve-Path $globalJson
+$json = Get-Content $globalJson | ConvertFrom-Json
+Write-Output "Updating SDK version from $($json.sdk.version) to $($versionResult.'latest-sdk')"
+$json.sdk.version = $versionResult.'latest-sdk'
+$json | ConvertTo-Json  | Out-File -Encoding utf8 $globalJson
+
+# Update RepoLayout.props file
+$propsPath = [System.IO.Path]::Combine($path, "RepoLayout.props")
+[xml]$props = Get-Content -Path $propsPath
+$nd = $props.SelectSingleNode("/Project/PropertyGroup/RuntimeFrameworkVersion")
+Write-Output "Updating Runtime version from $($nd.'#text') to $($versionResult.'latest-runtime')"
+$nd.'#text' = $versionResult.'latest-runtime'
+$settings = [System.Xml.XmlWriterSettings]@{
+  Encoding = $encoding
+  Indent   = $true    
+}
+$writer = [System.Xml.XmlWriter]::Create($propsPath, $settings)
+$nd.OwnerDocument.Save($writer)
+$writer.Dispose()
+