refactor: remove unneeded in Go 1.22 loop var copy (#4856)

The PR cleans up unnecessary loop variable copying and enables the
[`copyloopvar`](https://golangci-lint.run/usage/linters/#copyloopvar)
linter for detecting this redundant variable copying.

#### Additional notes

After the project upgraded to Go version 1.22 in #4779, copying
variables inside a `for` loop became unnecessary. See this [blog
post](https://go.dev/blog/loopvar-preview) for a detailed explanation.

The `copyloopvar` linter is only available from `golangci-lint` v1.57
onwards, so we also need to update this tool.

internal/pipe/blob/blob.go

@@ -57,7 +57,6 @@ func (Pipe) Publish(ctx *context.Context) error {
 	g := semerrgroup.New(ctx.Parallelism)
 	skips := pipe.SkipMemento{}
 	for _, conf := range ctx.Config.Blobs {
-		conf := conf
 		g.Go(func() error {
 			b, err := tmpl.New(ctx).Bool(conf.Disable)
 			if err != nil {