Data integrity: bump to cz 0.16.1, adjust sync mode. (apple#939)

- 0.16.1 changes an ext4 superblock setting that might have been causing
problems.
- apple#877 fixed an issue where the cache and sync settings for block
filesystems weren't being passed down to the VZ virtual machine
configuration. The default sync value getting passed down is `full`,
which reduces I/O performance. Relax this to use `fsync` for now.

## Type of Change
- [*] Bug fix
- [ ] New feature  
- [ ] Breaking change
- [ ] Documentation update

## Motivation and Context
May address problems reported in apple#877.

## Testing
- [x] Tested locally
- [ ] Added/updated tests
- [ ] Added/updated docs

Author: jglogan

Package.resolved

@@ -23,7 +23,7 @@ import PackageDescription
 let releaseVersion = ProcessInfo.processInfo.environment["RELEASE_VERSION"] ?? "0.0.0"
 let gitCommit = ProcessInfo.processInfo.environment["GIT_COMMIT"] ?? "unspecified"
 let builderShimVersion = "0.7.0"
-let scVersion = "0.16.0"
+let scVersion = "0.16.1"
 
 let package = Package(
     name: "container",

Package.swift

@@ -87,7 +87,7 @@ public struct Filesystem: Sendable, Codable {
     /// A block based filesystem.
     public static func block(
         format: String, source: String, destination: String, options: MountOptions, cache: CacheMode = .auto,
-        sync: SyncMode = .full
+        sync: SyncMode = .fsync
     ) -> Filesystem {
         .init(
             type: .block(format: format, cache: cache, sync: sync),
@@ -100,7 +100,7 @@ public struct Filesystem: Sendable, Codable {
     /// A named volume filesystem.
     public static func volume(
         name: String, format: String, source: String, destination: String, options: MountOptions,
-        cache: CacheMode = .auto, sync: SyncMode = .full
+        cache: CacheMode = .auto, sync: SyncMode = .fsync
     ) -> Filesystem {
         .init(
             type: .volume(name: name, format: format, cache: cache, sync: sync),