Signing source-build artifacts failing in 10.0.3xx

[NikolaMilosavljevic]

Build

Job: SB_CentOSStream10_Offline_PreviousSourceBuiltSdk_x64
Step: Sign Source-Built Artifacts (centOSStreamContainer)

##[error].packages/microsoft.dotnet.arcade.sdk/10.0.0-beta.26075.103/tools/Sign.proj(76,5): error : 'File 'dotnet-source-10.0.300-preview.0.26168.105.tar.gz' Certificate='LinuxSign500180PGP'' may only be signed with a detached signature. 'LinuxSign500180PGP' does not produce a detached signature

[mthalman]

@ellahathaway - Is this fixed by dotnet/dotnet#5574?

[ellahathaway]

It was resolved by dotnet/dotnet#5572. But dotnet/dotnet#5574 was the long-term fix.