[chore] Simplify release doc (#12563)

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#### Description
Simplifies description of automated release steps. While there is some
value in having the description of the automated steps somewhere, I
think this runs the risk of getting outdated and us having to look at
the code directly, so I would rather just remove it from here and
improve the comments/code of the automation over time. See
open-telemetry/opentelemetry-collector-releases/pull/856 for one
improvement of this kind.

Author: mx-psi

docs/release.md

@@ -40,7 +40,7 @@ Before the release, make sure there are no open release blockers in [core](https
 3. Manually run the action [Automation - Prepare Release](https://github.com/open-telemetry/opentelemetry-collector/actions/workflows/prepare-release.yml). This action will create an issue to track the progress of the release and a pull request to update the changelog and version numbers in the repo.
    - When prompted, enter the version numbers determined in Step 2, but do not include a leading `v`.
    - If not intending to release stable modules, do not specify a version for `Release candidate version stable`.
-   - **While this PR is open all merging in Core should be halted**. This should be enforced automatically: the `Merge freeze / Check` CI check will fail and the merge queue will reject PRs as long as there is an open PR with `[chore] Prepare release` in its title.
+   - While this PR is open all merging in Core is automatically halted via the `Merge freeze / Check` CI check.
    - If the PR needs updated in any way you can make the changes in a fork and PR those changes into the `prepare-release-prs/x` branch. You do not need to wait for the CI to pass in this prep-to-prep PR.
    -  🛑 **Do not move forward until this PR is merged.** 🛑
 
@@ -107,15 +107,7 @@ Before the release, make sure there are no open release blockers in [core](https
 
 The last step of the release process creates artifacts for the new version of the collector and publishes images to Dockerhub. The steps in this portion of the release are done in the [opentelemetry-collector-releases](https://github.com/open-telemetry/opentelemetry-collector-releases) repo.
 
-1. As of https://github.com/open-telemetry/opentelemetry-collector-releases/pull/684, sub-steps 1-4 below are now automated. Manually run GitHub Action workflow "Update Version in Distributions and Prepare PR" which will update the minor version automatically (e.g. v0.116.0 -> v0.117.0) or manually provide a new version if releasing a bugfix or skipping a version. Select "create pr" option to commit the changes and allow GitHub bot to create a draft PR with changes from sub-steps 1-3 included. Alternatively, you can run the ['bump-versions.sh' script locally in the opentelemetry-collector-releases repo](https://github.com/open-telemetry/opentelemetry-collector-releases/blob/main/.github/workflows/scripts/bump-versions.sh) with optional arguments for next version number(s) and whether to commit changes and create PR with GitHub CLI.
-
-   1. Update the `./distributions/**/manifest.yaml` files to include the new release version.
-
-   2. Update the builder version in `OTELCOL_BUILDER_VERSION` to the new release in the `Makefile`. While this might not be strictly necessary for every release, this is a good practice.
-
-   3. Run `make chlog-update VERSION="${RELEASE_VERSION}"` with the version of the artifacts.
-
-   4. Create a pull request with the change and ensure the build completes successfully. See [example](https://github.com/open-telemetry/opentelemetry-collector-releases/pull/71).
+1. Run the GitHub Action workflow "Update Version in Distributions and Prepare PR" which will update the minor version automatically (e.g. v0.116.0 -> v0.117.0) or manually provide a new version if releasing a bugfix or skipping a version. Select "create pr" option.
    -  🛑 **Do not move forward until this PR is merged.** 🛑
 
 2. Check out main and ensure it has the "Prepare release" commit in your local