ci(golangci-lint): update configuration and fix lint issues (#4247)

* ci: update golangci-lint configuration and lint settings

- Update golangci-lint to version 2
- Enable new linters and adjust existing ones
- Update lint settings across multiple test files
- Remove unused struct and variable checks
- Add new lint exclusions for generated code and specific directories

Signed-off-by: Flc <four_leaf_clover@foxmail.com>

* ci(github): update golangci-lint-action to v8 and lint version to v2.3.4

Signed-off-by: Flc <four_leaf_clover@foxmail.com>

* ci: downgrade golangci-lint to v2.1.6

Signed-off-by: Flc <four_leaf_clover@foxmail.com>

* ci(golangci): add gofumpt linter and fix related issues- Added gofumpt linter to .golangci.yml

Signed-off-by: Flc <four_leaf_clover@foxmail.com>

* test: ignore testifylint and gofumpt lints in specific test cases

Signed-off-by: Flc <four_leaf_clover@foxmail.com>

* build(deps): remove golang.org/x/lint

- Remove golang.org/x/lint package from go.mod
- Update related dependencies in go.sum

Signed-off-by: flc1125 <four_leaf_clover@foxmail.com>

* build(deps): downgrade golang.org/x/mod and golang.org/x/tools

- Downgrade golang.org/x/mod from v0.24.0 to v0.18.0
- Downgrade golang.org/x/tools from v0.33.0 to v.22.0

These changes are made to address compatibility issues with the current project setup.

Signed-off-by: flc1125 <four_leaf_clover@foxmail.com>

---------

Signed-off-by: Flc <four_leaf_clover@foxmail.com>
Signed-off-by: flc1125 <four_leaf_clover@foxmail.com>

internal/bytesconv/bytesconv_test.go

@@ -12,8 +12,10 @@ import (
 	"time"
 )
 
-var testString = "Albert Einstein: Logic will get you from A to B. Imagination will take you everywhere."
-var testBytes = []byte(testString)
+var (
+	testString = "Albert Einstein: Logic will get you from A to B. Imagination will take you everywhere."
+	testBytes  = []byte(testString)
+)
 
 func rawBytesToStr(b []byte) string {
 	return string(b)

internal/fs/fs.go

@@ -13,7 +13,6 @@ type FileSystem struct {
 // Open passes `Open` to the upstream implementation and return an [fs.File].
 func (o FileSystem) Open(name string) (fs.File, error) {
 	f, err := o.FileSystem.Open(name)
-
 	if err != nil {
 		return nil, err
 	}