golangci-lint does not support multi-module repositories

[kpurdon]

Describe the bug

The golangci-lint plugin fails when a repository contains multiple go.mod files (multiple Go modules). The plugin uses DEFAULT_SINGLE_PARTITION which runs all Go packages through a single golangci-lint invocation without respecting module boundaries. This causes golangci-lint to fail because it cannot resolve imports across separate modules.

Additionally, the default version is 1.64.6 (v1.x), while golangci-lint v2.x has been released with significant improvements and is now the recommended version.

Pants version
2.29.1

OS
Both MacOS and Linux

Additional info

A draft fix has been implemented in PR #22934.

Reproduction steps

1. Create a repository with two Go modules:
   mod_a/go.mod
   mod_a/main.go
   mod_b/go.mod
   mod_b/main.go
2. Run pants lint mod_a:: mod_b::
3. Observe golangci-lint fails due to module resolution issues

[kpurdon]

per https://www.pantsbuild.org/stable/docs/contributions#first-share-your-plan

ping =)