docs: Replace outdated backporting docs with link

README.md contained outdated instructions, so replace its contents with
a link to the more up-to-date backporting guide.

Signed-off-by: Tom Payne <tom@isovalent.com>

Documentation/contributing/release/backports.rst

@@ -66,8 +66,10 @@ One-time Setup
       $ git config --global user.email johndoe@example.com
 
 #. Make sure you have a GitHub developer access token with the ``public_repos``
-   scope available. For details, see `contrib/backporting/README.md
-   <https://github.com/cilium/cilium/blob/master/contrib/backporting/README.md>`_
+   scope available. You can do this directly from
+   https://github.com/settings/tokens or by opening GitHub and then navigating
+   to: User Profile -> Settings -> Developer Settings -> Personal access token
+   -> Generate new token.
 
 #. This guide makes use of several tools to automate the backporting process.
    The basics require ``bash`` and ``git``, but to automate interactions with
@@ -213,7 +215,7 @@ Via GitHub Web Interface
    backport PRs later.
 
 #. Mark all PRs you backported with the backport pending label
-   ``backport-pending/X.Y`` and clear the ``needs-backport/vX.Y`` label. This
+   ``backport-pending/X.Y`` and clear the ``needs-backport/X.Y`` label. This
    can be done with the command printed out at the bottom of the output from
    the ``start-backport`` script above (``GITHUB_TOKEN`` needs to be set for
    this to work).

contrib/backporting/README.md

@@ -1,71 +1,5 @@
 Cilium Backporting Scripts
 ==========================
 
-# check-stable - List commits that need backporting
-
-`GITHUB_TOKEN=xxx check-stable X.Y`
-
-The `check-stable` script scans for PRs which have been merged and marked with
-the label `needs-backport/X.Y`. The script will list those PRs and all non-merge
-commit ids that were part of the merge. There are three columns: first one is
-the correlated sha of the commit from the master branch, second one is the sha
-of the commit from the pull request, and third column is the commit subject.
-The sha from the master branch is then needed for backporting into downstream
-with the help of the `cherry-pick` script.
-
-## Example
-
-1. Generate a GitHub developer access token.
-   You can do this directly from https://github.com/settings/tokens or
-   by opening GitHub and then navigating to: User Profile -> Settings ->
-   Developer Settings -> Personal access token -> Generate new token
-
-   The access token requires access to the `public_repo` scope.
-
-   If not already done, install `jq` on your system.
-
-2. Run the script to generate the list of current backporting TODOs:
-
-   `GITHUB_TOKEN=xxx `./check-stable 1.0`
-
-   The list will be dumped to stdout.
-
-# cherry-pick - Cherry-pick individual commits
-
-`cherry-pick <commit-sha>`
-
-After having run `check-stable`, the `cherry-pick` script takes an individual
-commit sha as argument and adds the upstream commit into the downstream branch.
-It will also add a note about the upstream commit id into the commit message
-and the signed-off-by from the backporter.
-
-## Example
-
-1. Checkout one of the stable branches. Run `./check-stable` to get a TODO
-   list of commits to backport.
-
-2. Work through the list of commits dumped and pass a non-merge commit sha
-   to `cherry-pick`:
-
-   `./cherry-pick 479dd2d5a92a7035267bcdb91186c512ddd4379e`
-
-3. Resolve conflicts whenever necessary, and continue with the next commit.
-
-# set-labels.py - Set PR labels
-
-`set-labels.py <PR number> <action> <backport version>`
-
-The `set-labels.py` script is meant to keep the status of backporting changes
-up-to-date. The script takes the PR number to update, the action to take which
-can be "done" or "pending", and the backport version. This script needs the
-`GITHUB_TOKEN` environment variable set. Please provide a developer access
-token that has the `public_repo` scope as described in the steps above.
-
-## Example invocation
-
-The following invocation will set the "backport-done/1.7" label on the PRs
-10505 and 10651.
-
-```
-for pr in 10505 10651; do contrib/backporting/set-labels.py $pr done 1.7; done
-```
+See the [Backporting guide for the
+backporter](https://docs.cilium.io/en/latest/contributing/release/backports/#backporting-guide-for-the-backporter).