pr: ignore empty line after form feed char

[jfinkels]

Depends on #10303.

Fix a bug in pr where a newline character (\n) immediately following
a form feed character (\f) was incorrectly rendered as an extra blank
line in the output. After this commit, the newline is correctly ignored.

[codspeed-hq]

Merging this PR will degrade performance by 3.21%

❌ 1 regressed benchmark
✅ 281 untouched benchmarks
⏩ 38 skipped benchmarks¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Memory	dd_copy_partial	129.1 KB	133.4 KB	-3.21%

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_{Comparing jfinkels:pr-form-feed-newline (971017e) with main (2122c52)²}

Footnotes

1. 38 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (1a81d1b) during the generation of this report, so 2122c52 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩