Cache build directory of linux containers

SwiftPM uses caches heavily to reduce compilation and download time.
Before this change, we through these caches away with each container.

Sources/TaskCLI/GenerateDocumentation Command.swift

@@ -46,6 +46,7 @@ struct GenerateDocumentationCommand: Script {
 			try await docker(
 				"run", "--rm",
 				"-v", "\(tempDirectory.path):/code",
+				"-v", "swift-inotify-build-cache:/code/.build",
 				"--platform", Docker.getLinuxPlatformStringWithHostArchitecture(),
 				"-w", "/code",
 				"swift:latest",

Sources/TaskCLI/Test Command.swift

@@ -25,6 +25,7 @@ struct TestCommand: Script {
 			try await docker(
 				"run",
 				"-v", "\(currentDirectory):/code",
+				"-v", "swift-inotify-build-cache:/code/.build",
 				"--security-opt", "systempaths=unconfined",
 				"--platform", Docker.getLinuxPlatformStringWithHostArchitecture(),
 				"-w", "/code", "swift:latest",