.github: bound Go compiler parallelism during releases

Use conservative Go process and package limits while checking the source,\ninstalling GoReleaser, and building release binaries on the existing\nrunner. Keep the artifact build concurrency unchanged.

Co-authored-by: Shelley <shelley@exe.dev>

Author: maisem

.github/workflows/release.yml

@@ -12,6 +12,9 @@ jobs:
     runs-on: [self-hosted, tailmix-vm]
     container:
       image: golang:1.27.3
+    env:
+      GOMAXPROCS: "2"
+      GOFLAGS: "-p=1"
     steps:
       - uses: actions/checkout@v6
         with: