Fix underflow in `printAttrs`, `printList`

[roberth]

Description

The code that counts the number of elided attrs incorrectly used the per-printer "global" attribute counter instead of a counter that was relevant only to the current attribute set.

This bug flew under the radar because often the attribute sets aren't nested, not big enough, or we wouldn't pay attention to the numbers. I've noticed the issue because the difference underflowed.

Although this behavior is tested by the functional test lang/eval-fail-bad-string-interpolation-4.nix, the underflow slipped through review. A simpler reproducer would be as follows, but I haven't added it to the test suite to keep it simple and marginally faster.

$ nix run nix/2.23.1 -- eval --expr '"" + (let v = { a = { a = 1; b = 2; c = 1; d = 1; e = 1; f = 1; g = 1; h = 1; }; b = { a = 1; b = 1; c = 1; }; }; in builtins.deepSeq v v)'
error:
       … while evaluating a path segment
         at «string»:1:6:
            1| "" + (let v = { a = { a = 1; b = 2; c = 1; d = 1; e = 1; f = 1; g = 1; h = 1; }; b = { a = 1; b = 1; c = 1; }; }; in builtins.deepSeq v v)
             |      ^

       error: cannot coerce a set to a string: { a = { a = 1; b = 2; c = 1; d = 1; e = 1; f = 1; g = 1; h = 1; }; b = { a = 1; «4294967289 attributes elided» }; }

Motivation

I don't like bugs.

Context

Closes #10993

Priorities and Process

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[roberth]

cc @9999years