- upgrade to golangci-lint 2.6.1
- updates for gosec
- updates for govet
- updates for perfsprint
- updates modernize
Leaves out modernize:omitempty due to conflicts with tests
* fixed new gocritic violations
* fixed new 'contextcheck' violations
* fixed 'gosec' warnings
* suppressed ireturn and varnamelen linters
* fixed tenv violations, enabled building robustness tests on arm64
* fixed remaining linux failures
* makefile: fixed 'lint-all' target when running on arm64
* linter: increase deadline
* disable nilnil linter - to be enabled in separate PR