Stop skipping SDK content test on Azure Linux

[lbussell]

The SDK content test is skipped here based on the comment:

Since installation is done via RPM package, we just need to verify the package installation was done (handled by VerifyPackageInstallation test). There's no need to check the actual contents of the package.

dotnet-docker/tests/Microsoft.DotNet.Docker.Tests/SdkImageTests.cs

Lines 165 to 170 in b0ed3ba

	// Skip test on CBL-Mariner. Since installation is done via RPM package, we just need to verify the package installation
	// was done (handled by VerifyPackageInstallation test). There's no need to check the actual contents of the package.
	if (imageData.OS.StartsWith(OS.Mariner) || imageData.OS.StartsWith(OS.AzureLinux))
	{
	return;
	}

However, we no longer install any .NET packages via RPMs, so we should still check the contents of the SDK.

dotnet-docker/src/sdk/8.0/cbl-mariner2.0/amd64/Dockerfile

Lines 24 to 31 in 248742f

	# Install .NET SDK
	RUN curl -fSL --output dotnet.tar.gz https://dotnetcli.azureedge.net/dotnet/Sdk/$DOTNET_SDK_VERSION/dotnet-sdk-$DOTNET_SDK_VERSION-linux-x64.tar.gz \
	&& dotnet_sha512='8a4c637746177c4da6ceec63e23a1f499d61d050aa72bc599841550557ff7b1a15a034044c3987b230fdca4e5113de12b1676f5a2366e9946bd94aec1e51a42b' \
	&& echo "$dotnet_sha512 dotnet.tar.gz" | sha512sum -c - \
	&& tar -oxzf dotnet.tar.gz -C /usr/share/dotnet ./packs ./sdk ./sdk-manifests ./templates ./LICENSE.txt ./ThirdPartyNotices.txt \
	&& rm dotnet.tar.gz \
	# Trigger first run experience by running arbitrary cmd
	&& dotnet help

Related: #4845, #4845

[lbussell]

[Triage] We still use RPMs on CBL Mariner 2.0 + .NET 6. This test can still be skipped for that scenario, but should be enabled for all other .NET version and OS combinations.