release/dist: clamp min / max version for synology package centre (#13857)

Clamp the min and max version for DSM 7.0 and DSM 7.2 packages when we
are building packages for the synology package centre. This change
leaves packages destined for pkgs.tailscale.com with just the min
version set to not break packages in the wild / our update flow.

Updates https://github.com/tailscale/corp/issues/22908

Signed-off-by: Mario Minardi <mario@tailscale.com>

release/dist/synology/pkgs.go

@@ -155,8 +155,22 @@ func (t *target) mkInfo(b *dist.Build, uncompressedSz int64) []byte {
 		f("os_min_ver", "6.0.1-7445")
 		f("os_max_ver", "7.0-40000")
 	case 7:
-		f("os_min_ver", "7.0-40000")
-		f("os_max_ver", "")
+		if t.packageCenter {
+			switch t.dsmMinorVersion {
+			case 0:
+				f("os_min_ver", "7.0-40000")
+				f("os_max_ver", "7.2-60000")
+			case 2:
+				f("os_min_ver", "7.2-60000")
+			default:
+				panic(fmt.Sprintf("unsupported DSM major.minor version %s", t.dsmVersionString()))
+			}
+		} else {
+			// We do not clamp the os_max_ver currently for non-package center builds as
+			// the binaries for 7.0 and 7.2 are identical.
+			f("os_min_ver", "7.0-40000")
+			f("os_max_ver", "")
+		}
 	default:
 		panic(fmt.Sprintf("unsupported DSM major version %d", t.dsmMajorVersion))
 	}