ci: pin deno version to avoid test flakes

Author: evanw

.github/workflows/ci.yml

@@ -52,10 +52,12 @@ jobs:
         with:
           node-version: 16
 
-      - name: Setup Deno 1.x
+      # The version of Deno is pinned because version 1.25.1 was causing test
+      # flakes due to random segfaults.
+      - name: Setup Deno 1.24.0
         uses: denoland/setup-deno@main
         with:
-          deno-version: v1.x
+          deno-version: v1.24.0
 
       - name: Check out code into the Go module directory
         uses: actions/checkout@v2