ci: remove gpg signing from goreleaser

Signing requires GPG_FINGERPRINT env var which is not available in CI.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: genisd

goreleaser.yaml

@@ -43,15 +43,3 @@ release:
   extra_files:
   - glob: terraform-registry-manifest.json
     name_template: "{{ .ProjectName }}_{{ .Version }}_manifest.json"
-signs:
-- artifacts: checksum
-  args:
-  # If you are using this in a GitHub action or some other automated pipeline,
-  # you need to pass the batch flag to indicate its not interactive.
-  - --batch
-  - --local-user
-  - "{{ .Env.GPG_FINGERPRINT }}"  # set this environment variable for your signing key
-  - --output
-  - ${signature}
-  - --detach-sign
-  - ${artifact}