Cherry-pick: Use SWARMING_BOT_ID for archive machine
CL: https://r8-review.googlesource.com/c/r8/+/34924

Bug: 124643718
Change-Id: I9abd8fd0ce1f91716d08da2fd3427e8cdb257c5c
diff --git a/tools/archive.py b/tools/archive.py
index 659f411..c37b304 100755
--- a/tools/archive.py
+++ b/tools/archive.py
@@ -136,7 +136,7 @@
     with open(version_file,'w') as version_writer:
       version_writer.write('version.sha=' + GetGitHash() + '\n')
       version_writer.write(
-          'releaser=go/r8bot (' + os.environ.get('BUILDBOT_SLAVENAME') + ')\n')
+          'releaser=go/r8bot (' + os.environ.get('SWARMING_BOT_ID') + ')\n')
       version_writer.write('version-file.version.code=1\n')
 
     # TODO(127264123): Remove commented out files.