[llvm] [Py Reformat] Exclude `third-party` from reformat (PR #83491)

[Mircea Trofin via llvm-commits]

https://github.com/mtrofin created https://github.com/llvm/llvm-project/pull/83491

None

>From 4f5e55b91b31183d02f64dae491d1da21aa05e48 Mon Sep 17 00:00:00 2001
From: Mircea Trofin <mtrofin at google.com>
Date: Thu, 29 Feb 2024 14:00:16 -0800
Subject: [PATCH] [Py Reformat] Exclude `third-party` from reformat

---
 pyproject.toml | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 pyproject.toml

diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 00000000000000..b8313eb9fca450
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,6 @@
+[tool.black]
+extend-exclude = '''
+(
+  third-party/
+)
+'''