Drop macOS requirement to 10.15 with availability annotations

Package.swift

@@ -1,10 +1,10 @@
-// swift-tools-version: 6.0
+// swift-tools-version:5.9
 import PackageDescription
 
 let package = Package(
    name: "ErrorKit",
    defaultLocalization: "en",
-   platforms: [.macOS(.v13), .iOS(.v16), .tvOS(.v16), .watchOS(.v9), .macCatalyst(.v16)],
+   platforms: [.macOS(.v10_15), .iOS(.v16), .tvOS(.v16), .watchOS(.v9), .macCatalyst(.v16)],
    products: [.library(name: "ErrorKit", targets: ["ErrorKit"])],
    dependencies: [
       // CryptoKit is not available on Linux, so we need Swift Crypto

Sources/ErrorKit/Helpers/Logger+ErrorKit.swift

@@ -1,6 +1,7 @@
 #if canImport(OSLog)
 import OSLog
 
+@available(macOS 11, *)
 extension Logger {
    /// Logs a debug message with complete error chain description
    ///

Sources/ErrorKit/Helpers/String+ErrorKit.swift

@@ -2,12 +2,14 @@ import Foundation
 
 extension String {
    #if canImport(CryptoKit)
-   // On Apple platforms, use the modern localization API with Bundle.module
-   static func localized(key: StaticString, defaultValue: String.LocalizationValue) -> String {
-      return String(
-         localized: key,
-         defaultValue: defaultValue,
-         bundle: Bundle.module
+   // On Apple platforms, use the old localization API with Bundle.module
+   static func localized(key: StaticString, defaultValue: String) -> String {
+      return NSLocalizedString(
+         key.description,
+         tableName: nil,
+         bundle: Bundle.module,
+         value: defaultValue,
+         comment: defaultValue
       )
    }
    #else

Sources/ErrorKit/Logging/ErrorKit+OSLog.swift

@@ -60,6 +60,7 @@ extension ErrorKit {
    /// ```
    ///
    /// - See Also: ``exportLogFile(ofLast:minLevel:)`` for when you need a URL with the log content written to a text file
+   @available(macOS 13, *)
    public static func loggedData(ofLast duration: Duration, minLevel: OSLogEntryLog.Level = .notice) throws -> Data {
       let logStore = try OSLogStore(scope: .currentProcessIdentifier)
 
@@ -86,6 +87,7 @@ extension ErrorKit {
    /// - Throws: Errors if log store access fails or if writing to the file fails
    ///
    /// - See Also: ``loggedData(ofLast:minLevel:)`` for when you need the log content as Data directly
+   @available(macOS 13, *)
    public static func exportLogFile(ofLast duration: Duration, minLevel: OSLogEntryLog.Level = .notice) throws -> URL {
       let logData = try loggedData(ofLast: duration, minLevel: minLevel)
 
@@ -140,6 +142,7 @@ extension ErrorKit {
    ///     attachments: [logAttachment]
    /// )
    /// ```
+   @available(macOS 13, *)
    public static func logAttachment(
       ofLast duration: Duration,
       minLevel: OSLogEntryLog.Level = .notice,
@@ -157,6 +160,7 @@ extension ErrorKit {
    }
 }
 
+@available(macOS 13, *)
 extension Duration {
    /// Returns the duration as a `TimeInterval`.
    ///