Remove old lang explicit modules user default

Author: owenv

Sources/SWBCore/SWBFeatureFlag.swift

@@ -141,9 +141,6 @@ public enum SWBFeatureFlag {
     /// Remove this feature flag after landing rdar://104894978 (Write "perform-ownership-analysis" = "yes" to build manifest by default)
     public static let performOwnershipAnalysis = SWBFeatureFlagProperty("PerformOwnershipAnalysis", defaultValue: false)
 
-    /// Enable clang explicit modules by default.
-    public static let enableClangExplicitModulesByDefault = SWBFeatureFlagProperty("EnableClangExplicitModulesByDefault", defaultValue: false)
-
     /// Enable Swift explicit modules by default.
     public static let enableSwiftExplicitModulesByDefault = SWBFeatureFlagProperty("EnableSwiftExplicitModulesByDefault", defaultValue: false)
 

Sources/SWBCore/Settings/Settings.swift

@@ -573,10 +573,6 @@ final class WorkspaceSettings: Sendable {
             table.push(BuiltinMacros.EXPERIMENTAL_ALLOW_INSTALL_HEADERS_FILTERING, literal: true)
         }
 
-        if SWBFeatureFlag.enableClangExplicitModulesByDefault.value {
-            table.push(BuiltinMacros.CLANG_ENABLE_EXPLICIT_MODULES, literal: true)
-        }
-
         if SWBFeatureFlag.enableSwiftExplicitModulesByDefault.value {
             table.push(BuiltinMacros.SWIFT_ENABLE_EXPLICIT_MODULES, literal: .enabled)
         }