Replace 5.11 version with 6.0 in the code base (#7361)

This is a follow up to a corresponding toolchain PR
swiftlang/swift#71707.

Author: MaxDesiatov

Fixtures/Miscellaneous/DoNotFilterLinkerDiagnostics/Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.11
+// swift-tools-version: 6.0
 
 import PackageDescription
 

Fixtures/Miscellaneous/Plugins/DependentPlugins/Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.11
+// swift-tools-version: 6.0
 
 import PackageDescription
 

Fixtures/Miscellaneous/Plugins/MySourceGenPluginUsingURLBasedAPI/Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.11
+// swift-tools-version: 6.0
 import PackageDescription
 
 let package = Package(

Sources/Basics/SwiftVersion.swift

@@ -58,7 +58,7 @@ public struct SwiftVersion {
 extension SwiftVersion {
     /// The current version of the package manager.
     public static let current = SwiftVersion(
-        version: (5, 11, 0),
+        version: (6, 0, 0),
         isDevelopment: true,
         buildIdentifier: getBuildIdentifier()
     )

Sources/Build/BuildManifest/LLBuildManifestBuilder.swift

@@ -220,12 +220,12 @@ extension LLBuildManifestBuilder {
                 }
                 let additionalOutputs: [Node]
                 if command.outputFiles.isEmpty {
-                    if target.toolsVersion >= .v5_11 {
+                    if target.toolsVersion >= .v6_0 {
                         additionalOutputs = [.virtual("\(target.target.c99name)-\(command.configuration.displayName ?? "\(pluginNumber)")")]
                         phonyOutputs += additionalOutputs
                     } else {
                         additionalOutputs = []
-                        observabilityScope.emit(warning: "Build tool command '\(displayName)' (applied to target '\(target.target.name)') does not declare any output files and therefore will not run. You may want to consider updating the given package to tools-version 5.11 (or higher) which would run such a build tool command even without declared outputs.")
+                        observabilityScope.emit(warning: "Build tool command '\(displayName)' (applied to target '\(target.target.name)') does not declare any output files and therefore will not run. You may want to consider updating the given package to tools-version 6.0 (or higher) which would run such a build tool command even without declared outputs.")
                     }
                     pluginNumber += 1
                 } else {

Sources/Commands/PackageTools/Init.swift

@@ -83,7 +83,7 @@ extension SwiftPackageTool {
     }
 }
 
-#if swift(<5.11)
+#if swift(<6.0)
 extension InitPackage.PackageType: ExpressibleByArgument {}
 #else
 extension InitPackage.PackageType: @retroactive ExpressibleByArgument {}

Sources/Commands/Utilities/APIDigester.swift

@@ -328,7 +328,7 @@ extension SerializedDiagnostics.SourceLocation {
     }
 }
 
-#if swift(<5.11)
+#if swift(<6.0)
 extension SerializedDiagnostics.SourceLocation: DiagnosticLocation {}
 #else
 extension SerializedDiagnostics.SourceLocation: @retroactive DiagnosticLocation {}

Sources/CoreCommands/Options.swift

@@ -606,7 +606,7 @@ extension URL {
     }
 }
 
-#if swift(<5.11)
+#if swift(<6.0)
 extension BuildConfiguration: ExpressibleByArgument {}
 extension AbsolutePath: ExpressibleByArgument {}
 extension WorkspaceConfiguration.CheckingMode: ExpressibleByArgument {}

Sources/PackageDescription/Context.swift

@@ -24,7 +24,7 @@ public struct Context {
     }
 
     /// Information about the git status of a given package, if available.
-    @available(_PackageDescription, introduced: 5.11)
+    @available(_PackageDescription, introduced: 6.0)
     public static var gitInformation: GitInformation? {
         model.gitInformation.map {
             GitInformation(
@@ -45,7 +45,7 @@ public struct Context {
 }
 
 /// Information about the git status of a given package, if available.
-@available(_PackageDescription, introduced: 5.11)
+@available(_PackageDescription, introduced: 6.0)
 public struct GitInformation {
     public let currentTag: String?
     public let currentCommit: String

Sources/PackageLoading/TargetSourcesBuilder.swift

@@ -185,7 +185,7 @@ public struct TargetSourcesBuilder {
         }
 
         let additionalResources: [Resource]
-        if toolsVersion >= .v5_11 {
+        if toolsVersion >= .v6_0 {
             additionalResources = declaredResources.compactMap { resource in
                 if handledResources.contains(resource.path) {
                     return nil