chore: migrate to golangci-lint/v2

[hilmarf]

What this PR does / why we need it

I was checking originally on the linter issues in https://github.com/open-component-model/ocm-k8s-toolkit and realizing, that there is a newer version of golangci-lint available.

This PR upgrades to golangci-lint v2.1.5.

I've followed the https://golangci-lint.run/product/migration-guide/ and then added some more exclusions:

ocm/.github/config/golangci.yaml

Lines 141 to 172 in d50bee9

	- linters:
	- staticcheck
	path: cmds/.*|api/.*
	text: 'QF1008: could remove embedded field'
	- linters:
	- staticcheck
	path: cmds/.*|api/.*
	text: 'ST1006: receiver name should'
	- linters:
	- staticcheck
	path: cmds/.*|api/.*
	text: 'ST1001: should not use dot imports'
	- linters:
	- staticcheck
	path: cmds/.*|api/.*
	text: 'ST1005: error strings should not'
	- linters:
	- staticcheck
	path: cmds/.*|api/.*
	text: 'QF1001: could apply De Morgan'
	- linters:
	- staticcheck
	path: cmds/.*|api/.*
	text: 'QF1012: Use fmt.Fprintf'
	- linters:
	- staticcheck
	path: cmds/.*|api/.*
	text: 'QF1003: could use tagged switch'
	- linters:
	- staticcheck
	path: cmds/.*|api/.*
	text: 'QF1009: probably want to use time.Time.Equal'

until no more errors occurred.

Not sure if someone wants to fix some of those staticcheck.