Update swift-log dependency (#248)

* Update Package.swift

Update to the latest swift-log version.  This is driven by the desire to build swift-doc on Windows, which requires a newer version of swift-log.  This adjustment enables us to get further with building swift-doc on Windows.

* Update Package.resolved

Co-authored-by: Mattt <mattt@me.com>

Author: compnerd

Package.resolved

@@ -22,7 +22,7 @@ let package = Package(
         .package(url: "https://github.com/SwiftDocOrg/Markup.git", .upToNextMinor(from: "0.0.3")),
         .package(url: "https://github.com/NSHipster/SwiftSyntaxHighlighter.git", .revision("1.1.3")),
         .package(url: "https://github.com/apple/swift-argument-parser.git", .upToNextMinor(from: "0.3.1")),
-        .package(url: "https://github.com/apple/swift-log.git", .upToNextMinor(from: "1.2.0")),
+        .package(url: "https://github.com/apple/swift-log.git", .upToNextMinor(from: "1.4.2")),
         .package(name: "LoggingGitHubActions", url: "https://github.com/NSHipster/swift-log-github-actions.git", .upToNextMinor(from: "0.0.1")),
     ],
     targets: [