Add LZMA-SDK-9.22 to the license allowlist.

https://spdx.org/licenses/LZMA-SDK-9.22.html

chromium //third_party/lzma_sdk currently calls the license
"Public Domain":
https://source.chromium.org/chromium/chromium/src/+/main:third_party/lzma_sdk/README.chromium;l=6;drc=51397c51193b75500c2ae5ef5dcbc90638b69dc4

but LZMA-SDK-9.22 seems to be a better identifier for the license.

Change-Id: I0c0c237bbc52a0a5912d8f41b1f3c6a4a9663d77
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6093870
Auto-Submit: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Jordan Brown <rop@google.com>
Reviewed-by: Jordan Brown <rop@google.com>

metadata/fields/custom/license_allowlist.py

@@ -33,6 +33,7 @@ ALLOWED_SPDX_LICENSES = frozenset([
     # Public Domain variants.
     "ISC",
     "ICU",
+    "LZMA-SDK-9.22",
     "SunPro",
     "BSL-1.0",
 ])