fix: use --env-dev in CI so the dev conda environment is built

The CI install steps called `./install_shapepipe --develop`, but
`--develop` only adds dev pip extras into the *production* environment
(environment.yml). The flag that builds the dev conda env (shapepipe-dev,
from environment-dev.yml) is `--env-dev` — which also triggers the
`.[dev]` install on its own. The downstream test step already does
`conda activate shapepipe-dev`, an env the old flag never created.

Building production also failed to solve regardless: environment.yml pins
astropy==5.2 (py38–py311 builds only) against python=3.12, which is
unsatisfiable. That's a separate production-environment bug; this change
just points CI at the dev env it was always meant to use.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: cailmdaley

.github/workflows/ci-release.yml

@@ -52,12 +52,12 @@ jobs:
           CC: gcc-9
           CXX: g++-9
         if: runner.os == 'Linux'
-        run: ./install_shapepipe --develop
+        run: ./install_shapepipe --env-dev
 
       - name: Install package (macOS)
         shell: bash -l {0}
         if: runner.os == 'macOS'
-        run: ./install_shapepipe --develop
+        run: ./install_shapepipe --env-dev
 
       - name: Run tests
         shell: bash -l {0}