Bump mamba-org/setup-micromamba from 1.7.0 to 1.7.3 (#60)

Bumps [mamba-org/setup-micromamba](https://github.com/mamba-org/setup-micromamba) from 1.7.0 to 1.7.3.
- [Release notes](https://github.com/mamba-org/setup-micromamba/releases)
- [Commits](mamba-org/setup-micromamba@8752438...e820223)

---
updated-dependencies:
- dependency-name: mamba-org/setup-micromamba
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/deployment.yaml

@@ -19,7 +19,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Set up Conda environment with Micromamba
-        uses: mamba-org/setup-micromamba@8752438cc2755ab7d0de2a8d70b694f5586baae8
+        uses: mamba-org/setup-micromamba@e820223f89c8720d6c740ca154a7adf32fcd278a
         with:
            environment-file: envs/environment-test.yaml
            environment-name: salishsea-site-test