Revert "Promote fuchsia build v2 to prod. (#47729)"

This reverts commit 111808f3ffff8645e7fa2f188ca031e8468cd2c0.

.ci.yaml

diff --git a/.ci.yaml b/.ci.yaml
index b6b37d2..b6b83d5 100644
--- a/.ci.yaml
+++ b/.ci.yaml
@@ -159,7 +159,6 @@
     timeout: 60
 
   - name: Linux Fuchsia
-    bringup: true
     recipe: engine/engine
     properties:
       build_fuchsia: "true"
@@ -217,6 +216,7 @@
       - web_sdk/**
 
   - name: Linux linux_fuchsia
+    bringup: true
     recipe: engine_v2/engine_v2
     timeout: 60
     properties: