[PackageToolTests] Disable pinning test pending investigation
[PackageToolTests] Disable pinning test pending investigation

Disabling this test until I figure out the exact issue.

apple/swift-package-manager,JGiola/swift-package-manager,sschiau/swift-package-manager,vmanot/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,vmanot/swift-package-manager,abertelrud/swift-package-manager,JGiola/swift-package-manager,JGiola/swift-package-manager,JGiola/swift-package-manager,vmanot/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,sschiau/swift-package-manager,vmanot/swift-package-manager,sschiau/swift-package-manager,JGiola/swift-package-manager,vmanot/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,sschiau/swift-package-manager,sschiau/swift-package-manager