ci: install from wheel artifact in PyPITests; add arm64; fix triggers

Author: claude

.github/workflows/ci.yml

@@ -5,8 +5,6 @@ on:
     branches:
       - main
       - '[0-9]+.[0-9]+.x'
-    tags:
-      - v[0-9]+.[0-9]+.[0-9]+
   pull_request:
     branches:
       - main
@@ -30,7 +28,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        platform: ["ubuntu-latest", "macos-latest", "macos-15-intel", "windows-latest", "windows-11-arm"]
+        platform: ["ubuntu-latest", "ubuntu-24.04-arm", "macos-latest", "macos-15-intel", "windows-latest", "windows-11-arm"]
         python-version: [3.11, 3.12, 3.13, 3.14]
         dep-versions: [Latest]
         no-extras: ['']
@@ -55,6 +53,7 @@ jobs:
     - uses: actions/download-artifact@v8
       with:
         name: wheels-${{ matrix.platform }}
+        path: .
 
     - name: Set flag to install minimum dependencies
       if: ${{ matrix.dep-versions == 'Minimum' }}
@@ -73,6 +72,7 @@ jobs:
         old-build: ${{ matrix.no-extras != 'No Extras' && matrix.dep-versions == 'Minimum' }}
         need-cartopy: ${{ matrix.no-extras != 'No Extras' }}
         install-flags: ${{ env.INSTALL_FLAGS }}
+        wheel-dir: .
 
     - name: Run tests
       uses: ./.github/actions/run-tests
@@ -106,6 +106,9 @@ jobs:
   # TestsSDist:
 
   # TestsConda:
+  #   Placeholder — conda test job internals require a separate exploration spike.
+  #   Must be implemented before v1.8.0 ships (conda is a primary distribution channel).
+  #   See .claude/specs/2026-03-13-ci-workflow-restructure-design.md § Open Issues
 
   # Docs: