remove pub syntax for container fields

lib/std/zig/parser_test.zig

@@ -1766,7 +1766,7 @@ test "zig fmt: struct declaration" {
         \\const S = struct {
         \\    const Self = @This();
         \\    f1: u8,
-        \\    pub f3: u8,
+        \\    f3: u8,
         \\
         \\    fn method(self: *Self) Self {
         \\        return self.*;
@@ -1777,14 +1777,14 @@ test "zig fmt: struct declaration" {
         \\
         \\const Ps = packed struct {
         \\    a: u8,
-        \\    pub b: u8,
+        \\    b: u8,
         \\
         \\    c: u8,
         \\};
         \\
         \\const Es = extern struct {
         \\    a: u8,
-        \\    pub b: u8,
+        \\    b: u8,
         \\
         \\    c: u8,
         \\};