Bump to version v21.1 for release

Summary:
  * Updates of run parameters for `salish`, `sockeye`, `graham`, and `orcinus`.
  * Changed to install dependency packages exclusively from conda-forge channel
  * Added GitHub Actions workflows for CodeQL analysis, and docs linkcheck.
  * Changed to use Python 3.9 for development (3.5 on orcinus)
  * Renamed Git default branch from `master` to `main`.
  * Enabled version control system (VCS) revision recording for Git
    repositories.
  * Changed continuous integration from Bitbucket pipeline to GitHub Actions
    workflow.
  * Migrated from Mercurial on Bitbucket to Git on GitHub due to Bitbucket's
    decision to terminate support for Mercurial.
  * Added `split-results` sub-command to split the results of a multi-day
    SalishSeaCast NEMO model run (e.g. a hindcast run) into daily results
    directories.

salishsea_cmd/__init__.py

@@ -12,4 +12,4 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
-__version__ = "21.1.dev0"
+__version__ = "21.1"