move some package management related source files around

src/Package.zig

@@ -1,7 +1,7 @@
 pub const Module = @import("Package/Module.zig");
 pub const Fetch = @import("Package/Fetch.zig");
 pub const build_zig_basename = "build.zig";
-pub const Manifest = @import("Manifest.zig");
+pub const Manifest = @import("Package/Manifest.zig");
 
 pub const Path = struct {
     root_dir: Cache.Directory,

src/Package/Fetch.zig

@@ -1449,9 +1449,9 @@ const Allocator = std.mem.Allocator;
 const Cache = std.Build.Cache;
 const ThreadPool = std.Thread.Pool;
 const WaitGroup = std.Thread.WaitGroup;
-const Manifest = @import("../Manifest.zig");
 const Fetch = @This();
 const main = @import("../main.zig");
-const git = @import("../git.zig");
+const git = @import("Fetch/git.zig");
 const Package = @import("../Package.zig");
+const Manifest = Package.Manifest;
 const ErrorBundle = std.zig.ErrorBundle;

src/Package/Fetch/git.zig

@@ -11,8 +11,6 @@ const Allocator = mem.Allocator;
 const Sha1 = std.crypto.hash.Sha1;
 const assert = std.debug.assert;
 
-const ProgressReader = @import("Package.zig").ProgressReader;
-
 pub const oid_length = Sha1.digest_length;
 pub const fmt_oid_length = 2 * oid_length;
 /// The ID of a Git object (an SHA-1 hash).