chore: lower dependabot noise

We have the Cargo.lock file checked in. This means that dependabot
opens PR for every version change. That creates a lot of noise. I
care about breaking new releases. This new config should hopefully
fix that.

Author: vmx

.github/dependabot.yml

@@ -4,6 +4,9 @@ updates:
     directory: "/"
     schedule:
       interval: "daily"
+    ignore:
+      - dependency-name: "*"
+        update-types: ["version-update:semver-minor", "version-update:semver-patch"]
 
   - package-ecosystem: "github-actions"
     directory: "/"