updatecli: set force to false, it won't try to update the base branch

[v1v]

What does this PR do?

Set force to false, it won't try to update the base branch

Why is it important?

See updatecli/updatecli#2211 (comment)

We have seen some commits were wiped out, even though they were there originally:

• [Automation] Bump Golang version to 1.22.11 #6663

Hence a follow-up was created partially:

• [Automation] Bump Golang version to 1.22.12 #6700

Taht should not happen but I see in the logs

WARNING: branch "refs/heads/updatecli_main_901223529a6beca5c9cb3180f1dae9731c8da4e9c40169d7042cc0163a6d7e24" diverged from "refs/heads/main", resetting it to "refs/heads/main"
".go-version" updated with content "1.22.11"
--- .go-version
+++ .go-version
@@ -1 +1 @@
-1.22.10
+1.22.11

when using

Application:	0.91.0
Golang     :	1.23.4 linux/amd64
Build Time :	2024-12-24T06:53:18Z

Checklist

• I have read and understood the pull request guidelines of this project.
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in ./changelog/fragments using the changelog tool
• I have added an integration test or an E2E test

Disruptive User Impact

How to test this PR locally

in the CI, I ran https://github.com/elastic/elastic-agent/actions/runs/13142093773/job/36671485235

Related issues

Questions to ask yourself

• How are we going to support this in production?
• How are we going to measure its adoption?
• How are we going to debug this?
• What are the metrics I should take care of?
• ...