fix: preserve _dist layout expected by make dist

Removing no_unique_dist_dir and switching binary to a flat name
changed the _dist/ directory structure goreleaser produces. The
existing make dist target (used by release.yml for Azure uploads)
walks _dist/ subdirectories and names archives after them, so it
would have started producing incorrectly named artifacts. Restoring
the OS-arch subdirectory layout keeps that path working; the new
archives section in this file names GitHub Release assets
independently, so it is unaffected.

Signed-off-by: Benoit Tigeot <benoit.tigeot@lifen.fr>

.goreleaser.yaml

@@ -55,8 +55,8 @@ builds:
       - goos: windows
         goarch: loong64
     main: ./cmd/helm
-    binary: helm
+    no_unique_dist_dir: true
-    mod_timestamp: "{{ .CommitTimestamp }}"
+    binary: "{{ .Os }}-{{ .Arch }}/helm"
     ldflags:
       - -w -s
       - -extldflags "-static"