docs(actions): drop the dependabot ignore advice for the v0 action tag

The note said dependabot reads `@v0` as the version `0` rather than as a
major-version pin, and told users to ignore `rvben/rumdl` in
`.github/dependabot.yml`. Both halves are wrong.

The downgrade PRs came from the default 3-day package cooldown GitHub enabled
for every ecosystem on 2026-07-14: dependabot works out that a moving major tag
is already current, then the cooldown filter discards that answer and re-picks
the newest tag older than the window. That is why the proposed version always
lagged the tag by a release or two, why it hit `v1`-style tags on other actions
too, and why it started on a date rather than always having been the case.
Fixed upstream on 2026-08-04 (dependabot/dependabot-core#15738).

The remedy was worse than the diagnosis: `ignore` by dependency-name is total,
so it also suppresses the eventual `v0` to `v1` migration, permanently, to work
around a bug that no longer exists.

Author: rvben

README.md

@@ -492,19 +492,6 @@ jobs:
 
 The `v0` tag always points to the latest stable release, following GitHub Actions conventions.
 
-Dependabot reads `@v0` as the version `0` rather than as a major-version pin, so it opens PRs titled
-`bump rvben/rumdl from 0 to 0.2.x`. Merging one replaces the moving tag with a fixed version, which is
-the opposite of what `@v0` is for. To keep tracking the tag, ignore the action in
-`.github/dependabot.yml`:
-
-```yaml
-updates:
-  - package-ecosystem: github-actions
-    directory: /
-    ignore:
-      - dependency-name: rvben/rumdl
-```
-
 #### Inputs
 
 | Input         | Description                            | Default        |

docs/usage/ci-cd.md

@@ -24,19 +24,6 @@ jobs:
 
 The `v0` tag always points to the latest stable release.
 
-Dependabot reads `@v0` as the version `0` rather than as a major-version pin, so it opens PRs titled
-`bump rvben/rumdl from 0 to 0.2.x`. Merging one replaces the moving tag with a fixed version, which is
-the opposite of what `@v0` is for. To keep tracking the tag, ignore the action in
-`.github/dependabot.yml`:
-
-```yaml
-updates:
-  - package-ecosystem: github-actions
-    directory: /
-    ignore:
-      - dependency-name: rvben/rumdl
-```
-
 ### Action Inputs
 
 | Input         | Description              | Default        |