chore: Update build instructions for build image

Signed-off-by: Christian Haudum <[email protected]>

Makefile

@@ -664,7 +664,7 @@ else
 endif
 
 build-image: ensure-buildx-builder
-	$(SUDO) $(BUILD_OCI) --build-arg=GO_VERSION=$(GO_VERSION) -t $(IMAGE_PREFIX)/loki-build-image:$(IMAGE_TAG) ./loki-build-image
+	$(SUDO) $(BUILD_OCI) --build-arg=GO_VERSION=$(GO_VERSION) -t $(IMAGE_PREFIX)/loki-build-image:$(BUILD_IMAGE_VERSION) ./loki-build-image
 build-image-push: build-image ## push the docker build image
 ifneq (,$(findstring WIP,$(IMAGE_TAG)))
 	@echo "Cannot push a WIP image, commit changes first"; \

docs/sources/community/maintaining/release-loki-build-image.md

@@ -14,23 +14,11 @@ if any changes were made in the folder `./loki-build-image/`.
 
 **To build and use the `loki-build-image`:**
 
-## Step 1
-
-1. Create a branch with the desired changes to the Dockerfile.
-2. Update the version tag of the `loki-build-image` pipeline defined in `.drone/drone.jsonnet` (search for `pipeline('loki-build-image')`) to a new version number (try to follow semver).
-3. Run `DRONE_SERVER=https://drone.grafana.net/ DRONE_TOKEN=<token> make drone` and commit the changes to the same branch.
-   1. The `<token>` is your personal drone token, which can be found by navigating to https://drone.grafana.net/account.
-4. Create a PR.
-5. Once approved and merged to `main`, the image with the new version is built and published.
-   {{% admonition type="note" %}}
-   Keep an eye on https://drone.grafana.net/grafana/loki for the build after merging ([example](https://drone.grafana.net/grafana/loki/17760/1/2)).
-   {{% /admonition %}}
-
-## Step 2
-
-1. Create a branch.
-2. Update the `BUILD_IMAGE_VERSION` variable in the `Makefile`.
-3. Run `loki-build-image/version-updater.sh <new-version>` to update all the references.
-4. Run `DRONE_SERVER=https://drone.grafana.net/ DRONE_TOKEN=<token> make drone` to update the Drone config to use the new build image.
-5. Create a new PR.
-
+1. Create a branch with the desired changes to the `./loki-build-image/Dockerfile`.
+1. Update the `BUILD_IMAGE_VERSION` variable in the `Makefile`.
+1. Commit your changes.
+1. Run `make build-image-push` to build and publish the new version of the build image.
+1. Run `make release-workflows` to update the Github workflows.
+1. Commit your changes.
+1. Push your changes to the remote branch.
+1. Open a PR against the `main` branch.