xz (Lzma) (bazelbuild#1465)

@dzbarsky 

Do you think the xz, xzdec and lzmadec targets are needed too? I had
them disabled as only lzma was building, but I think lzma is the only
target that gets linked into any builds and xz is just for building a
standalone binary? Let me know your thoughts and I'll clean up this pr
to finalise.

resolves bazelbuild#1275

---------

Co-authored-by: Yun Peng <pcloudy@google.com>
Co-authored-by: Vertexwahn <julian.amann@tum.de>

modules/xz/5.4.5/MODULE.bazel

@@ -0,0 +1,7 @@
+module(
+    name = "xz",
+    version = "5.4.5",
+)
+
+bazel_dep(name = "platforms", version = "0.0.8")
+bazel_dep(name = "bazel_skylib", version = "1.5.0")