fix: invalid goreleaser artifacts name for signing step (#1380)

```
    # Which artifacts to sign
    #
    # Valid options are:
    # - none        no signing
    # - all:        all artifacts
    # - checksum:   checksum files
    # - source:     source archive
    # - package:    Linux packages (deb, rpm, apk, etc)
    # - installer:  Installers (MSI, NSIS, macOS Pkgs) (GoReleaser Pro)
    # - diskimage:  macOS DMG disk images (GoReleaser Pro)
    # - archive:    archives from archive pipe
    # - sbom:       any SBOMs generated for other artifacts
    # - binary:     binaries (only when `archives.format` is 'binary', use binary_signs otherwise)
    #
    # Default: 'none'.
    artifacts: all
```


https://goreleaser.com/customization/sign/sign/

Author: jooola

.goreleaser.yml

@@ -125,7 +125,7 @@ checksum:
   algorithm: sha256
 
 signs:
-  - artifacts: checksums
+  - artifacts: checksum
     signature: ${artifact}.sig
     id: hcloud-sign
     args: