Update dependency com_github_bazelbuild_buildtools to v7.3.1

Author: renovate[bot]

WORKSPACE

@@ -56,9 +56,9 @@ http_archive(
 
 http_archive(
     name = "com_github_bazelbuild_buildtools",
-    sha256 = "39c59cb5352892292cbe3174055aac187edcb5324c9b4e2d96cb6e40bd753877",
-    strip_prefix = "buildtools-7.1.2",
-    url = "https://github.com/bazelbuild/buildtools/archive/refs/tags/v7.1.2.tar.gz",
+    sha256 = "051951c10ff8addeb4f10be3b0cf474b304b2ccd675f2cc7683cdd9010320ca9",
+    strip_prefix = "buildtools-7.3.1",
+    url = "https://github.com/bazelbuild/buildtools/archive/refs/tags/v7.3.1.tar.gz",
 )
 
 http_archive(