Remove the linux_build_command

Author: shahmishal

.github/workflows/pull_request.yml

@@ -17,7 +17,6 @@ jobs:
     uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@main
     with:
       linux_os_versions: '["jammy"]'
-      linux_build_command: 'swift test'
       linux_swift_versions: '["nightly-main", "nightly-6.2"]'
       windows_swift_versions: '["nightly-main"]'
       windows_build_command: 'Invoke-Program swift test'