Add charmcraft 3 support

Summary of changes:
- Update the charmcraft.yaml file to use base and platforms, only
  allowing noble support.
- Update config to default to caracal.
- Update osci.yaml to use the charmcraft 3.x/beta
- Drop non-noble tests
- Update constraints file from -2024.1.txt to -noble.txt
- Add charmbuild to .zuul.yaml

Change-Id: I4f09f3a4549d35f3fb57235aaddee2ff997a2a49

.zuul.yaml

@@ -2,3 +2,8 @@
     templates:
       - openstack-python3-charm-jobs
       - openstack-cover-jobs
+    check:
+      jobs:
+        - charmbuild
+    vars:
+      charm_build_name: watcher

charmcraft.yaml

@@ -9,16 +9,22 @@ parts:
       - python3-dev
     source: src/
     build-snaps:
-      - charm
+      - charm/latest/edge
     build-environment:
       - CHARM_INTERFACES_DIR: $CRAFT_PROJECT_DIR/interfaces/
       - CHARM_LAYERS_DIR: $CRAFT_PROJECT_DIR/layers/
-bases:
-  - build-on:
-      - name: ubuntu
-        channel: "22.04"
-        architectures: [amd64]
-    run-on:
-      - name: ubuntu
-        channel: "22.04"
-        architectures: [amd64, arm64, ppc64el, s390x]
+
+base: ubuntu@24.04
+platforms:
+ amd64:
+   build-on: amd64
+   build-for: amd64
+ arm64:
+   build-on: arm64
+   build-for: arm64
+ ppc64el:
+   build-on: ppc64el
+   build-for: ppc64el
+ s390x:
+   build-on: s390x
+   build-for: s390x

osci.yaml

@@ -6,4 +6,4 @@
       needs_charm_build: true
       charm_build_name: watcher
       build_type: charmcraft
-      charmcraft_channel: 2.x/stable
+      charmcraft_channel: 3.x/stable

src/metadata.yaml

@@ -9,8 +9,6 @@ description: |
   OpenStack Train or later is required.
 tags:
   - openstack
-series:
-  - jammy
 subordinate: false
 requires:
   shared-db: