fix: correct shell syntax error in release workflow (#23)

Fix syntax error on lines 36-37 where the cp command for
radar-agent-linux-arm64-musl was split across two lines without
proper line continuation, causing bash to interpret the second
line as a command.

This was causing the workflow to fail with:
"radar-agent-linux-arm64-musl: command not found"

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

Co-authored-by: Claude <[email protected]>

Author: ajGingrich

.github/workflows/release.yml

@@ -34,7 +34,6 @@ jobs:
           cp ./binaries/radar-agent-linux/radar-agent-linux ./radar-agent-linux
           cp ./binaries/radar-agent-linux-musl/radar-agent-linux-musl ./radar-agent-linux-musl
           cp ./binaries/radar-agent-linux-arm64/radar-agent-linux-arm64 ./radar-agent-linux-arm64
-            radar-agent-linux-arm64-musl
           cp ./binaries/radar-agent-linux-arm64-musl/radar-agent-linux-arm64-musl ./radar-agent-linux-arm64-musl
           cp ./binaries/radar-agent-darwin/radar-agent-darwin ./radar-agent-darwin