fix: retain symlinks added to zip archives (#3585)

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fixes #3584 

When following the reproduction steps in #3584 I now get the following
contents for the zip archive:
```
$ goreleaser --snapshot --skip-publish
...
$ (mkdir thezip && cd thezip && unzip ../dist/test_0.0.0-SNAPSHOT-none_darwin_amd64.zip) && ls -lR thezip
Archive:  ../dist/test_0.0.0-SNAPSHOT-none_darwin_amd64.zip
  inflating: a/x                     -> ../x 
  inflating: a/x2                    -> x 
  inflating: x                       
  inflating: test                    
finishing deferred symbolic links:
  a/x                    -> ../x
  a/x2                   -> x
total 1640
drwxr-xr-x  4 orawlings  staff     128 Nov 22 16:19 a
-rwxr-xr-x  1 orawlings  staff  833104 Nov 22 16:19 test
-rw-r--r--  1 orawlings  staff       2 Nov 22 15:32 x

thezip/a:
total 0
lrwxr-xr-x  1 orawlings  staff  4 Nov 22 16:19 x -> ../x
lrwxr-xr-x  1 orawlings  staff  1 Nov 22 16:19 x2 -> x
```

<!-- Why is this change being made? -->

I'm using goreleaser for a project that packages multiple binaries in
zip archives. We also include symlinks within the zip archives to give
some of the binaries an alternate (usually shorter) spelling so they are
easier to invoke on the command line.

This brings the zip archive behavior regarding symlinks in line with
tar.gz and tar archives.

<!-- # Provide links to any relevant tickets, URLs or other resources
-->

pkg/archive/zip/zip.go

@@ -5,8 +5,10 @@ package zip
 import (
 	"archive/zip"
 	"compress/flate"
+	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 
 	"github.com/goreleaser/goreleaser/pkg/config"
 )
@@ -57,9 +59,17 @@ func (a Archive) Add(f config.File) error {
 	if err != nil {
 		return err
 	}
-	if info.IsDir() || info.Mode()&os.ModeSymlink != 0 {
+	if info.IsDir() {
 		return nil
 	}
+	if info.Mode()&os.ModeSymlink != 0 {
+		link, err := os.Readlink(f.Source) // #nosec
+		if err != nil {
+			return fmt.Errorf("%s: %w", f.Source, err)
+		}
+		_, err = io.WriteString(w, filepath.ToSlash(link))
+		return err
+	}
 	file, err := os.Open(f.Source) // #nosec
 	if err != nil {
 		return err

pkg/archive/zip/zip_test.go

@@ -2,6 +2,7 @@ package zip
 
 import (
 	"archive/zip"
+	"bytes"
 	"io"
 	"io/fs"
 	"os"
@@ -85,6 +86,13 @@ func TestZipFile(t *testing.T) {
 		}
 		if zf.Name == "link.txt" {
 			require.True(t, zf.FileInfo().Mode()&os.ModeSymlink != 0)
+			rc, err := zf.Open()
+			require.NoError(t, err)
+			var link bytes.Buffer
+			_, err = io.Copy(&link, rc)
+			require.NoError(t, err)
+			rc.Close()
+			require.Equal(t, link.String(), "regular.txt")
 		}
 	}
 	require.Equal(t, []string{