derive: replace ahash with rustc-hash

[Kijewski]

ahash shines when you hash very long inputs, in excess of 1000 bytes. We only hash file names, variable names, block names … which should for all reasonable applications less than 100 bytes in length.

rustc-hash does not claim to be DoS-resistent like ahash is, but we only operate on trusted data, so this feature is not needed.

See also: https://blog.goose.love/posts/rosetta-hashing/.

The performance is mostly unchanged or slightly improved:

hello_world             time:   [61.157 µs 61.336 µs 61.503 µs]
                        change: [-3.5829% -2.8333% -2.0098%] (p = 0.00 < 0.05)
                        Performance has improved.

item_info.html          time:   [69.987 µs 70.137 µs 70.277 µs]
                        change: [-2.5459% -2.1263% -1.7360%] (p = 0.00 < 0.05)
                        Performance has improved.

item_union.html         time:   [185.41 µs 185.80 µs 186.18 µs]
                        change: [-2.9272% -2.4197% -1.9278%] (p = 0.00 < 0.05)
                        Performance has improved.

page.html               time:   [747.83 µs 748.66 µs 749.58 µs]
                        change: [-0.3883% -0.1132% +0.1551%] (p = 0.43 > 0.05)
                        No change in performance detected.

print_item.html         time:   [158.28 µs 158.72 µs 159.28 µs]
                        change: [-1.9084% -1.4402% -0.9742%] (p = 0.00 < 0.05)
                        Change within noise threshold.

short_item_info.html    time:   [133.45 µs 133.66 µs 133.89 µs]
                        change: [-4.0600% -3.7956% -3.5459%] (p = 0.00 < 0.05)
                        Performance has improved.

sidebar.html            time:   [207.27 µs 207.74 µs 208.28 µs]
                        change: [-3.7883% -3.2903% -2.8108%] (p = 0.00 < 0.05)
                        Performance has improved.

source.html             time:   [122.85 µs 123.15 µs 123.53 µs]
                        change: [-1.0462% -0.5575% -0.0943%] (p = 0.03 < 0.05)
                        Change within noise threshold.

type_layout.html        time:   [158.98 µs 159.46 µs 160.00 µs]
                        change: [+0.5711% +0.9257% +1.2877%] (p = 0.00 < 0.05)
                        Change within noise threshold.

type_layout_size.html   time:   [75.699 µs 75.978 µs 76.250 µs]
                        change: [-2.6748% -1.9573% -1.0695%] (p = 0.00 < 0.05)
                        Performance has improved.

[GuillaumeGomez]

In our case, it should be more than enough. Thanks!