Rollup merge of #125158 - Nilstrieb:block-indent, r=compiler-errors

hir pretty: fix block indent

before:
```rust
fn main() {
        {
                {
                        ::std::io::_print(format_arguments::new_const(&["Hello, world!\n"]));
                    };
            }
    }
```
after:
```rust
fn main() {
    {
        {
            ::std::io::_print(format_arguments::new_const(&["Hello, world!\n"]));
        };
    }
}
```

AST pretty does the same.

compiler/rustc_hir_pretty/src/lib.rs

@@ -1454,7 +1454,7 @@ impl<'a> State<'a> {
                     self.word_space(":");
                 }
                 // containing cbox, will be closed by print-block at `}`
-                self.cbox(INDENT_UNIT);
+                self.cbox(0);
                 // head-box, will be closed by print-block after `{`
                 self.ibox(0);
                 self.print_block(blk);