FreeBSD: Deprecate TCP_PCAP_OUT and TCP_PCAP_IN

FreeBSD removed these upstream in [1], so deprecate them here. This
resolves a recent CI failure.

These constants were originally added in [2].

[1]: freebsd/freebsd-src@6e76489
[2]: rust-lang#1151

(backport <rust-lang#4381>)
(cherry picked from commit c8f0910)

Author: tgross35

libc-test/build.rs

@@ -2855,6 +2855,9 @@ fn test_freebsd(target: &str) {
             "CAP_UNUSED0_44" | "CAP_UNUSED0_57" | "CAP_UNUSED1_22" | "CAP_UNUSED1_57"
             | "CAP_ALL0" | "CAP_ALL1" => true,
 
+            // FIXME(freebsd): Removed in FreeBSD 15, deprecated in libc
+            "TCP_PCAP_OUT" | "TCP_PCAP_IN" => true,
+
             _ => false,
         }
     });

src/unix/bsd/freebsdlike/freebsd/mod.rs

@@ -3771,7 +3771,9 @@ pub const TCP_PERF_INFO: c_int = 78;
 pub const TCP_LRD: c_int = 79;
 pub const TCP_KEEPINIT: c_int = 128;
 pub const TCP_FASTOPEN: c_int = 1025;
+#[deprecated(since = "0.2.171", note = "removed in FreeBSD 15")]
 pub const TCP_PCAP_OUT: c_int = 2048;
+#[deprecated(since = "0.2.171", note = "removed in FreeBSD 15")]
 pub const TCP_PCAP_IN: c_int = 4096;
 pub const TCP_FUNCTION_BLK: c_int = 8192;
 pub const TCP_FUNCTION_ALIAS: c_int = 8193;