https://bugs.gentoo.org/972369

Add __init__.py to chromium's bundled pyjson5 directories so they
are treated as regular packages. Without these, a system-installed
pyjson5 package (which has __init__.py) takes priority over the
bundled one during import resolution, causing build failures.

--- a/src/3rdparty/chromium/third_party/pyjson5/__init__.py
+++ b/src/3rdparty/chromium/third_party/pyjson5/__init__.py
@@ -0,0 +1 @@
+# This file makes pyjson5 a regular package to prevent shadowing by system pyjson5.
--- a/src/3rdparty/chromium/third_party/pyjson5/src/__init__.py
+++ b/src/3rdparty/chromium/third_party/pyjson5/src/__init__.py
@@ -0,0 +1 @@
+# This file makes pyjson5.src a regular package to prevent shadowing by system pyjson5.