Revert "[manifest] Add 3pp repo to infra checkout"

This reverts commit 69dbcfa4da39ee9a8682692bcebcf17343e39296.

Reason for revert: breaks local checkouts, unclear why

Original change's description:
> [manifest] Add 3pp repo to infra checkout
>
> This will automatically add 3pp to everyone's checkouts of the infra
> Jiri workspace, and start indexing it in Code Search.
>
> Change-Id: I815d63e5f0e386ab8c8c268e1ae0f8e76e65b2a6
> Reviewed-on: https://fuchsia-review.googlesource.com/c/manifest/+/708923
> Reviewed-by: Rob Mohr <mohrr@google.com>

Change-Id: Iadb9dcac2d5d6c56046c50c4dccfbade2ed475de
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://fuchsia-review.googlesource.com/c/manifest/+/708924
Reviewed-by: RubberStamper 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/infra b/infra
index 8645dc8..db0a81d 100644
--- a/infra
+++ b/infra
@@ -12,10 +12,6 @@
              path="fuchsia/manifest"/>
     <!-- Name things <gerrit-host-prefix> so that this can be imported
          into other manifests that pull in infra repos from multiple hosts. -->
-    <project name="fuchsia/3pp"
-             path="fuchsia/3pp"
-             remote="https://fuchsia.googlesource.com/infra/3pp"
-             gerrithost="https://fuchsia-review.googlesource.com"/>
     <project name="fuchsia/infra"
              path="fuchsia/infra"
              remote="https://fuchsia.googlesource.com/infra/infra"