ci: defer creating major version tag until release (#108)

Previously, we were always setting the `version` tag (e.g., 16, 17) when building
a container image. However, version 17 is still in beta and was tagged with `17`,
which could cause confusion. Users might mistake it for a stable release,
and tools like Renovate might attempt to update to this version.

This change ensures that the major `version` tag is not created until the version
is officially released.

Signed-off-by: Jonathan Gonzalez V <jonathan.gonzalez@enterprisedb.com>
Signed-off-by: Niccolò Fei <niccolo.fei@enterprisedb.com>
Co-authored-by: Niccolò Fei <niccolo.fei@enterprisedb.com>

.github/generate-strategy.sh

@@ -8,9 +8,12 @@
 #
 set -eu
 
+ROOT_DIR=$(cd "$(dirname "$0")/../"; pwd)
+source "${ROOT_DIR}/lib/repo_funcs.sh"
+
 # Define an optional aliases for some major versions
 declare -A aliases=(
-	[16]='latest'
+	[$POSTGRESQL_LATEST_MAJOR_RELEASE]='latest'
 )
 
 # Define the current default distribution
@@ -66,13 +69,18 @@ generator() {
 
 		# Additional aliases in case we are running in the default distro
 		# i.e. "14", "14.2", "14.2-1", "latest"
-		if [ "${distro}" == "${DEFAULT_DISTRO}" ]; then
+		if [[ "${distro}" == "${DEFAULT_DISTRO}" ]]; then
 			versionAliases+=(
-				"$version"
 				"${postgresImageVersion}"
 				"${postgresImageVersion}-${releaseVersion}"
 				${aliases[$version]:+"${aliases[$version]}"}
 			)
+			# Create a tag with just the major (e.g "14") only for stable versions
+			if [[ "${version}" -le "${POSTGRESQL_LATEST_MAJOR_RELEASE}" ]]; then
+				versionAliases+=(
+					"$version"
+				)
+			fi
 		fi
 
 		# Supported platforms for container images