Update @gerritcodereview/typescript-api to 3.9.1

Change-Id: Iee464deb00a49d4325f0f38a4c1f90e2ca37bfe8
Release-Notes: skip
diff --git a/plugins/package.json b/plugins/package.json
index 9e92086..4a4bf03 100644
--- a/plugins/package.json
+++ b/plugins/package.json
@@ -26,7 +26,7 @@
     "@codemirror/search": "^6.5.4",
     "@codemirror/state": "^6.2.1",
     "@codemirror/view": "^6.20.2",
-    "@gerritcodereview/typescript-api": "3.8.0",
+    "@gerritcodereview/typescript-api": "3.9.1",
     "@open-wc/testing": "^3.2.0",
     "@polymer/decorators": "^3.0.0",
     "@polymer/polymer": "^3.5.1",
diff --git a/plugins/yarn.lock b/plugins/yarn.lock
index 21ec522..045fcb5 100644
--- a/plugins/yarn.lock
+++ b/plugins/yarn.lock
@@ -425,10 +425,10 @@
   dependencies:
     "@types/chai" "^4.2.12"
 
-"@gerritcodereview/typescript-api@3.8.0":
-  version "3.8.0"
-  resolved "https://registry.yarnpkg.com/@gerritcodereview/typescript-api/-/typescript-api-3.8.0.tgz#2e418b814d7451c40365b2dc4f88e9965ece0769"
-  integrity sha512-wUkIWUx99Rj1vxRYQISxyzN0nplqu7t5sRDyJ8R3yNNkvALQAMC6Whj63qzCsZsymVFzC5up3y+ZVxaeh7b+xA==
+"@gerritcodereview/typescript-api@3.9.1":
+  version "3.9.1"
+  resolved "https://registry.yarnpkg.com/@gerritcodereview/typescript-api/-/typescript-api-3.9.1.tgz#c532e9a39e3d5f16f6a5cb5691988c04cd477531"
+  integrity sha512-5t8CBhlqQEcjJqNld1/ajcdZjjyrv7vsn4u0N3mX4hc4DnPJimIjYVFvP8nLyhSkioawWDIRLvzlmfzFs02lDg==
 
 "@jridgewell/resolve-uri@^3.1.0":
   version "3.1.1"