Fix publishing workflows in dockerhub

[NyakudyaA]

Feature description

Currently the workflows allow publishing the following image tags

• kartoza/postgis:17-3.5--v2024.10.20 > with the last date being the date the image is pushed
• kartoza/postgis:17-3.5 - Latest version
• kartoza/postgis:latest - We tag the latest

Each time a PR is merged, we are always updating the kartoza/postgis:17-3.5 image, this is not ideal especially for people who use these in production

Additional context

Solution

We need to adjust the action to be able to do the following

Publish the following tags and updates

New version of postgis

• kartoza/postgis:17-3.5--v2024.10.20 > with the last date being the date the image is pushed
• kartoza/postgis:17-3.5 - Latest version
• kartoza/postgis:latest - We tag the latest

Update of existing tag i.e 17-3.5

When a PR is merged we need to check if kartoza/postgis:17-3.5 already exists, if so we skip updating it but only update the following

• kartoza/postgis:17-3.5--v2024.10.20 > with the last date being the date the image is pushed
• kartoza/postgis:latest - We tag the latest

Only the kartoza/postgis:17-3.5 - should be updated only if there is a bug or any security updates