v0.70.0

## Demo: `change-with-nth`

https://github.com/user-attachments/assets/40abe7e6-8c98-4a13-85b7-17e69372ef9e

## Summary

- Added `change-with-nth` action for dynamically changing the `--with-nth` option.
    - Requires `--with-nth` to be set initially.
    - Multiple options separated by `|` can be given to cycle through.
  ```sh
  echo -e "a b c\nd e f\ng h i" | fzf --with-nth .. \
    --bind 'space:change-with-nth(1|2|3|1,3|2,3|)'
  ```
- Added `change-header-lines` action for dynamically changing the `--header-lines` option
- Performance improvements (1.3x to 1.9x faster filtering depending on query)
  ```
  === query: 'l' ===
    [all]   baseline:   168.87ms  current:    95.21ms  (1.77x)  matches: 5069891 (94.78%)
    [1T]    baseline:  1652.22ms  current:   841.40ms  (1.96x)  matches: 5069891 (94.78%)

  === query: 'lin' ===
    [all]   baseline:   343.27ms  current:   252.59ms  (1.36x)  matches: 3516507 (65.74%)
    [1T]    baseline:  3199.89ms  current:  2230.64ms  (1.43x)  matches: 3516507 (65.74%)

  === query: 'linux' ===
    [all]   baseline:    85.47ms  current:    63.72ms  (1.34x)  matches: 307229 (5.74%)
    [1T]    baseline:   774.64ms  current:   589.32ms  (1.31x)  matches: 307229 (5.74%)

  === query: 'linuxlinux' ===
    [all]   baseline:    55.13ms  current:    35.67ms  (1.55x)  matches: 12230 (0.23%)
    [1T]    baseline:   461.99ms  current:   332.38ms  (1.39x)  matches: 12230 (0.23%)

  === query: 'linuxlinuxlinux' ===
    [all]   baseline:    51.77ms  current:    32.53ms  (1.59x)  matches: 865 (0.02%)
    [1T]    baseline:   409.99ms  current:   296.33ms  (1.38x)  matches: 865 (0.02%)
  ```
- Fixed `nth` attribute merge order to respect precedence hierarchy (#4697)
- bash: Replaced `printf` with builtin `printf` to bypass local indirections (#4684) (@DarrenBishop)