Add preamble.json to release targets

We need to keep track of the version number in preamble.json for the
operator index image.

Let's make sure we add it to the makefile targets for releasing the
operator so that it's included in the release commit.

Author: rhmdnd

Makefile

@@ -459,7 +459,7 @@ git-release: fetch-git-tags package-version-to-tag changelog
 	git checkout -b "release-v$(TAG)"
 	sed -i "s/\(.*Version = \"\).*/\1$(TAG)\"/" version/version.go
 	sed -i "s/\(.*VERSION?=\).*/\1$(TAG)/" version.Makefile
-	git add version* bundle CHANGELOG.md config/manifests/bases
+	git add version* bundle CHANGELOG.md config/manifests/bases catalog/preamble.json
 	git restore config/manager/kustomization.yaml
 
 .PHONY: fetch-git-tags