ci: improve release process and test coverage (#553)

- Add extra_files configuration to .goreleaser.yaml
- Include .xz and .xz.sha256 files in the release

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

Reviewed-on: https://gitea.com/gitea/tea/pulls/553
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: techknowlogick <techknowlogick@noreply.gitea.io>
Co-authored-by: Bo-Yi Wu <appleboy.tw@gmail.com>
Co-committed-by: Bo-Yi Wu <appleboy.tw@gmail.com>

.goreleaser.yaml

@@ -117,5 +117,10 @@ gitea_urls:
   api: https://gitea.com/api/v1
   download: https://gitea.com
 
+release:
+  extra_files:
+    - glob: ./**.xz
+    - glob: ./**.xz.sha256
+
 # yaml-language-server: $schema=https://goreleaser.com/static/schema-pro.json
 # vim: set ts=2 sw=2 tw=0 fo=cnqoj