C++ Repos: adding release branch protection (#65)

Release branches were not protected, and so CI pass was not enforced.
This change enables branch protection for the pattern used in up-cpp
release branches and sets an approval threshold for each category of
branch based on the relative "stability" of the branch/repo.

otterdog/eclipse-uprotocol.jsonnet

@@ -165,7 +165,19 @@ orgs.newOrg('eclipse-uprotocol') {
       web_commit_signoff_required: false,
       branch_protection_rules: [
         orgs.newBranchProtectionRule('main') {
-          required_approving_review_count: 0,
+          required_approving_review_count: 1,
+          required_status_checks+: [
+            "CI status checks"
+          ],
+        },
+        orgs.newBranchProtectionRule('v*.*_up-v*.*.*') {
+          required_approving_review_count: 1,
+          required_status_checks+: [
+            "CI status checks"
+          ],
+        },
+        orgs.newBranchProtectionRule('up-v1.5.7') {
+          required_approving_review_count: 2,
           required_status_checks+: [
             "CI status checks"
           ],
@@ -455,6 +467,12 @@ orgs.newOrg('eclipse-uprotocol') {
             "CI status checks"
           ],
         },
+        orgs.newBranchProtectionRule('v*.*_up-v*.*.*') {
+          required_approving_review_count: 1,
+          required_status_checks+: [
+            "CI status checks"
+          ],
+        },
       ],
     },
     orgs.newRepo('up-transport-zenoh-python') {