chore(deps): remove dependabot version updates

Renovate is the version-update bot. GitHub Dependabot alerts stay.

.github/dependabot.yml

@@ -1,35 +0,0 @@
-version: 2
-updates:
-  - package-ecosystem: "npm"
-    directory: "/"
-    schedule:
-      interval: "weekly"
-    commit-message:
-      prefix: "chore(deps)"
-    groups:
-      minor-and-patch:
-        update-types:
-          - "minor"
-          - "patch"
-    ignore:
-      # @types/node must track the runtime Node major, not the latest release.
-      # This stack's Lambdas run on nodejs24.x, so @types/node is pinned to ^24.
-      # Dependabot can't see the Lambda runtime and a too-new types major still
-      # compiles, so a major bump passes CI while being wrong at runtime. This is
-      # the sanctioned exception to the no-blanket-ignore rule (engineering-handbook
-      # github-standards Pinning Principle). Bump deliberately alongside a runtime
-      # upgrade. Minor/patch within the current major still flow.
-      - dependency-name: "@types/node"
-        update-types: ["version-update:semver-major"]
-
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      interval: "weekly"
-    commit-message:
-      prefix: "chore(deps)"
-    groups:
-      minor-and-patch:
-        update-types:
-          - "minor"
-          - "patch"