chore: add Dependabot configuration file

A new `dependabot.yml` file has been added to the `.github` directory. This configuration file enables Dependabot to check for updates in our package ecosystems (i.e., `github-actions` and `gomod`) on a weekly schedule, focusing on security updates for the `gomod` ecosystem specifically.

.github/dependabot.yml

@@ -0,0 +1,32 @@
+# https://docs.github.com/en/code-security/dependabot
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "chore(gha)"
+
+  # only open security update PRs (see linked docs for explanation of `open-pull-requests-limit: 0`)
+  #  https://docs.github.com/en/code-security/dependabot/dependabot-security-updates/configuring-dependabot-security-updates#overriding-the-default-behavior-with-a-configuration-file
+  #  https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#open-pull-requests-limit
+
+  # security PRs need to be further enabled in the repository settings
+  #  https://docs.github.com/en/code-security/dependabot/dependabot-auto-triage-rules/customizing-auto-triage-rules-to-prioritize-dependabot-alerts
+
+  - package-ecosystem: "gomod"
+    open-pull-requests-limit: 0
+    directory: "/components/notebook-controller"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "fix(deps)"
+
+  - package-ecosystem: "gomod"
+    open-pull-requests-limit: 0
+    directory: "/components/odh-notebook-controller"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "fix(deps)"