ci: pin goreleaser project_name

The slim Dockerfile runs goreleaser inside a container where the
project name can't be guessed; set it explicitly so nested builds
work.

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.goreleaser.yaml

@@ -1,5 +1,7 @@
 version: 2
 
+project_name: cloudreve
+
 before:
   hooks:
     - go mod tidy