Update all the PRs on tag creation/push on reference branch

[apomalyn]

Currently, the version is updated when the action is triggered by a pull request, but as a developer, I would like my PRs to be updated when my reference branch is updated or when a new tag is created.

Behaviour wanted

Scenario 1

I update/label/unlabeled/sync my pull request -> Check if this PR needs to be update, do so

Scenario 2

I merge a PR on the reference branch (main) -> Check all the other PR and update them.

Example:
Context:

• main branch version: 1.0.0
• PR#1 version (patch label) : 1.0.1
• PR#2 version (minor label): 1.1.0
• PR#3 version (minor labe): 1.1.0

PR#2 is merged:

• main branch version: 1.1.0
• PR#1 version (patch label): 1.0.1
• PR#3 version (minor labe): 1.1.0

The action run:

• Check PR#1
  • Update the version to 1.1.1
• Check PR#3
  • Update the version to 1.2.0

Scenario 3

I create a new tag -> Check all the other PR and update them.

Example:
Context:

• Last tag version: 1.0.0
• PR#1 version (patch label) : 1.0.1
• PR#2 version (minor label): 1.1.0
• PR#3 version (minor labe): 1.1.0

PR#2 is merged:

• Last tag version: 1.1.0
• PR#1 version (patch label): 1.0.1
• PR#3 version (minor labe): 1.1.0

The action run:

• Check PR#1
  • Update the version to 1.1.1
• Check PR#3
  • Update the version to 1.2.0