Mergo Related Build issues

[mallardduck]

Describe the bug
We reverted bumps to mergo due to it causing build issues: #539

Then I dug deeper and found k8s long standing issue about this topic here: kubernetes/kubernetes#107499

At minimum BRO repo needs to adjust renovate to ignore the package.
Maybe we consider reverting the mergo pin to use v0.3.5 like the k8s issue says.

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That in mind, there are two (and a half) portions to fixing this issue:

1. Immediate Solution: Add this package to renovate config ignore,
2. Medium Term Solution: Evaluate if BRO/Wranger even depend on the behaviour changes that happen on varying mergo versions,
   2.5 Consider Being the BEST FOSS community members: Do we dare consider to go fix the root issues behind this 2-3+ year long issue? Would first need to be fixed at mergo package, then they would (in theory) cut a v1.0.1 then kubernetes repo needs to be updated. THEN finally we as Rancher can update Wrangler and stuff.

[mallardduck]

Assigned @jbiers to work on part 1 of the issue. I'm not sure the best way to do task 2 though; so we won't rush that idea.
Once you've corrected the renovate config and we've merged that PR, we'll just have you un-assign the issue.

Alternatively, you could also make a new issue to split out the Renovate change (mainly for tracking your work since it doesn't require QA).

[jbiers]

The immediate solution was implemented in PR #542

[MKlimuszka]

Proper fix is blocked until there are upstream changes.

[mallardduck]

Update on upstream changes concerns; k8s group confirmed they plan to remove the library. PRs to remove it are in progress and once they do merge those we can adjust wrangler accordingly and BRO after that.

[mallardduck]

Upstream k8s has removed mergo as of this PR kubernetes/kubernetes#126764
This will land in 1.32 from the looks of it, so I created an issue on wrangler repo for frameworks team to follow up when the time comes.

[mallardduck]

I've closed the wrangler issue I created as this is an issue I suspect will naturally resolve itself once we are working on Rancher 2.11 (i.e. adding 1.32 k8s support). Since the upstream go code removes the library in 1.32 k8s. For now I'll leave this open as tech debt simply to remind us to clean up the renovate config around when that happens.