Rust build fails on OpenBSD after using file_lock feature

PR 130999 added the file_lock feature, but doesn't included OpenBSD in the supported targets (Tier 3 platform), leading to a compilation error ("try_lock() not supported").

Author: semarie

library/std/src/sys/fs/unix.rs

@@ -1263,6 +1263,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn lock(&self) -> io::Result<()> {
@@ -1275,6 +1276,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn lock(&self) -> io::Result<()> {
@@ -1286,6 +1288,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn lock_shared(&self) -> io::Result<()> {
@@ -1298,6 +1301,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn lock_shared(&self) -> io::Result<()> {
@@ -1309,6 +1313,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn try_lock(&self) -> Result<(), TryLockError> {
@@ -1329,6 +1334,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn try_lock(&self) -> Result<(), TryLockError> {
@@ -1343,6 +1349,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn try_lock_shared(&self) -> Result<(), TryLockError> {
@@ -1363,6 +1370,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn try_lock_shared(&self) -> Result<(), TryLockError> {
@@ -1377,6 +1385,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     ))]
     pub fn unlock(&self) -> io::Result<()> {
@@ -1389,6 +1398,7 @@ impl File {
         target_os = "fuchsia",
         target_os = "linux",
         target_os = "netbsd",
+        target_os = "openbsd",
         target_vendor = "apple",
     )))]
     pub fn unlock(&self) -> io::Result<()> {