docs: update hacktober prep tracker after require_descriptive_names.sh run

[priya-sundaram-dev]

Per @cclauss's request on #15081, updating docs/hacktober_2026_prep.md to reflect the scripts/close_pull_requests_with_require_descriptive_names.sh run, which produced:

CLOSED_COUNT=14 CLOSED_PRS=14677,14321,14082,14061,14028,14022,13989,13912,13772,13691,13679,13676,13675,13413

Changes:

• Checked off ([ ] -> [x]) those 14 lines and relabeled each as "closed by close_pull_requests_with_require_descriptive_names.sh".
• Updated the Closed totals table: close_pull_requests_with_require_descriptive_names.sh 0 -> 14, and Total 39 -> 53.

No lines other than those 14 (and the totals row) are touched.

[cclauss]

I just ran scripts/close_pull_requests_with_failing_tests.sh which output:

CLOSED_COUNT=95 CLOSED_PRS=15174,15128,15057,15025,15021,14975,14974,14972,14938,14835,14818,14731,14727,14723,14717,14700,14690,14680,14625,14618,14617,14616,14594,14524,14518,14511,14510,14507,14486,14480,14468,14455,14336,14332,14331,14304,14300,14297,14290,14286,14285,14283,14272,14270,14269,14261,14256,14234,14227,14098,14096,14088,14085,14080,14057,14040,14034,14000,13983,13967,13958,13943,13942,13935,13916,13899,13897,13879,13878,13839,13816,13810,13799,13790,13789,13746,13745,13671,13653,13646,13605,13595,13585,13558,13552,13544,13541,13536,13526,13520,13506,13485,13457,13009,12956