[infra] Skip unnecessary build step for QEMU RISCV64.

Change-Id: Ib7bef7aa9e0f4b76815749268c4990393a2342b1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/330686
Reviewed-by: Jonas Termansen <sortie@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
diff --git a/tools/bots/test_matrix.json b/tools/bots/test_matrix.json
index 987502c..61433f75 100644
--- a/tools/bots/test_matrix.json
+++ b/tools/bots/test_matrix.json
@@ -1036,14 +1036,6 @@
           ]
         },
         {
-          "name": "build dart",
-          "script": "tools/build.py",
-          "arguments": [
-            "--arch=simriscv64",
-            "gen_snapshot"
-          ]
-        },
-        {
           "name": "vm unit tests",
           "arguments": [
             "-nvm-linux-${mode}-riscv64-qemu",