Replace OpenStack's CLA enforcement with the DCO

The OpenStack project will be switching from the OpenInfra
Individual Contributor License Agreement to the Developer
Certificate of Origin, which requires that commit messages include a
Signed-Off-By trailer. Any commits generated by automated tooling
will need to comply with this requirement as well. Simply including
git commit's -s option on the command line should be sufficient to
meet this requirement.

Some SIG repos inherit from meta-config but explicitly disabled CLA
enforcement, so switch those to disabling DCO enforcement instead.

Depends-On: https://review.opendev.org/950463
Change-Id: Ia9a82d055bf71a1d7b0c56e162c167c39167e9ab

gerrit/acls/openstack/ansible-collections-openstack.config

@@ -13,4 +13,4 @@
 	createSignedTag = group ansible-collections-openstack-release
 
 [receive]
-	requireContributorAgreement = false
+	requireSignedOffBy = false

gerrit/acls/openstack/ansible-role-container-registry.config

@@ -7,4 +7,4 @@
 	label-Workflow = -1..+1 group ansible-role-container-registry-core
 
 [receive]
-	requireContributorAgreement = false
+	requireSignedOffBy = false

gerrit/acls/openstack/ldappool.config

@@ -7,4 +7,4 @@
 	label-Workflow = -1..+1 group ldappool-core
 
 [receive]
-	requireContributorAgreement = false
+	requireSignedOffBy = false

gerrit/acls/openstack/liberasurecode.config

@@ -11,4 +11,4 @@
 	createSignedTag = group liberasurecode-release
 
 [receive]
-	requireContributorAgreement = false
+	requireSignedOffBy = false

gerrit/acls/openstack/meta-config.config

@@ -19,7 +19,7 @@
 
 [receive]
 	requireChangeId = true
-	requireContributorAgreement = true
+	requireSignedOffBy = true
 
 [submit]
 	mergeContent = true

gerrit/acls/openstack/puppet-ceph.config

@@ -14,4 +14,4 @@
 	createSignedTag = group puppet-ceph-release
 
 [receive]
-	requireContributorAgreement = false
+	requireSignedOffBy = false