Create pyca/infra

This is similar in purpose to the upstream
https://github.com/pyca/infra project where dockerfiles for building
custom manylinux builder images are kept.  I would like to try
building manylinux2014_aarch64 images, so need an untrusted project to
do that with speculative testing.

Change-Id: I2da4e73c92dc46429fa52dd7b7b924458ad3832e

gerrit/acls/pyca/infra.config

@@ -0,0 +1,13 @@
+[access "refs/heads/*"]
+abandon = group opendev-project-config-core
+label-Code-Review = -2..+2 group opendev-project-config-core
+label-Workflow = -1..+1 group opendev-project-config-core
+
+[access "refs/tags/*"]
+pushSignedTag = group opendev-project-config-release
+
+[receive]
+requireChangeId = true
+
+[submit]
+mergeContent = true

gerrit/projects.yaml

@@ -5662,6 +5662,8 @@
   description: An OpenStack fault injection library
 - project: performa/shaker
   description: Distributed data-plane performance testing tool
+- project: pyca/infra
+  description: Docker containers and related things for pyca building
 - project: pyca/project-config
   description: Project configuration for 3rd party CI for Python Crytographic Authority
 - project: recordsansible/ansible-role-ara

zuul/main.yaml

@@ -1631,6 +1631,7 @@
                 - secret
                 - nodeset
         untrusted-projects:
+          - pyca/infra
           - zuul/zuul-jobs
       github:
         untrusted-projects: