Create dependabot.yml and pin conda action (#35)

.github/dependabot.yml

@@ -0,0 +1,11 @@
+# Dependabot version updates. See docs for configuration options:
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every month
+      interval: "monthly"

.github/workflows/env-checks.yml

@@ -59,7 +59,7 @@ jobs:
           fi;
 
       # create the conda env
-      - uses: conda-incubator/setup-miniconda@v3
+      - uses: conda-incubator/setup-miniconda@a4260408e20b96e80095f42ff7f1a15b27dd94ca  # v3.0.4
         with:
           python-version: ${{ matrix.python-version }}
           auto-update-conda: true