Update to gazelle 0.12.0 and run hack/update-bazel.sh

vendor/github.com/d2g/dhcp4/BUILD

@@ -8,6 +8,7 @@ go_library(
         "option.go",
         "packet.go",
     ],
+    importmap = "vendor/github.com/d2g/dhcp4",
     importpath = "github.com/d2g/dhcp4",
     visibility = ["//visibility:public"],
 )

vendor/github.com/d2g/dhcp4client/BUILD

@@ -6,12 +6,9 @@ go_library(
         "client.go",
         "generatexid.go",
         "inetsock.go",
-    ] + select({
-        "@io_bazel_rules_go//go/platform:linux": [
-            "pktsock_linux.go",
-        ],
-        "//conditions:default": [],
-    }),
+        "pktsock_linux.go",
+    ],
+    importmap = "vendor/github.com/d2g/dhcp4client",
     importpath = "github.com/d2g/dhcp4client",
     visibility = ["//visibility:public"],
     deps = [