1. Does this PR affect any open issues?(Y/N) :

• N
• Y
  ench Enhancement: Support Overriding Existing Artifacts When Pushing Packages #645

2. What is the scope of this PR (e.g. component or file name):

• pkg/client/client_test.go
• pkg/client/push.go
• pkg/client/push_test.go
• scripts/reg.sh

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

This PR adds the possibility to override (replace) existing .tar artifacts in the remote registry (e.g., Artifactory) when pushing a package.
Motivation: In our CI process, we need to push updates to the same artifact name frequently, and deleting old packages before push is not convenient.
Adds --force flag to the kpm push command
If the artifact exists and the flag is set, the push operation replaces the existing object
No behavior change unless the flag is used

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• N
• Y

The default behavior does not change. Overriding only happens when the new flag is explicitly set.

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• Unit test
• Integration test
• Benchmark (add benchmark stats below)
• Manual test (add detailed scripts or steps below)
• Other

Push a tar artifact with a given name to the registry.
Re-push the same artifact with the new flag enabled (--force).
Confirm that the existing artifact is replaced without a deletion step.
Push one more time without force and get an error with already esixts