Rollup merge of #150529 - rustbot:docs-update, r=ehuss

Update books

## rust-lang/reference

21 commits in ec78de0ffe2f8344bd0e222b17ac7a7d32dc7a26..6363385ac4ebe1763f1e6fb2063c0b1db681a072
2025-12-15 16:17:43 +0000 to 2025-12-31 21:12:35 +0000
- Remove cargo workspace inheritance (rust-lang/reference#2129)
- identifiers: bump Unicode from 16 to 17 (rust-lang/reference#2071)
- Fix alternation order of lexical rules (rust-lang/reference#2126)
- Fix overly greedy digits (rust-lang/reference#2124)
- Clarify UNICODE_ESCAPE valid token value (rust-lang/reference#2123)
- Fix ambiguity of RESERVED_RAW_IDENTIFIER (rust-lang/reference#2122)
- Document how closure capturing interacts with discriminant reads (rust-lang/reference#1837)
- operator-expr: remove stray word in footnote (rust-lang/reference#2118)
- await-expr: add a missing space (rust-lang/reference#2120)
- attributes: add missing punctuation to instruction_set (rust-lang/reference#2117)
- associated-items: add missing periods (rust-lang/reference#2116)
- Move tools into a consolidated cargo workspace (rust-lang/reference#2115)
- Unwrap all of the lexical chapters (rust-lang/reference#2113)
- Unwrap const_eval.md (rust-lang/reference#2112)
- Add section on expansion-time (early) name resolution (rust-lang/reference#2055)
- const_eval.md: add missing word (rust-lang/reference#2068)
- path-expr.md: use a more suitable punctuation (rust-lang/reference#2082)
- items: clarify label for type-aliases documentation (rust-lang/reference#2110)
- do not mix singular and plural (rust-lang/reference#2101)
- external-blocks: add missing "and" in list (rust-lang/reference#2111)
- conditional-compilation: add a space in `cfg.cfg_attr.attribute-list` (rust-lang/reference#2109)

## rust-lang/rust-by-example

2 commits in 7d21279e40e8f0e91c2a22c5148dd2d745aef8b6..2e02f22a10e7eeb758e6aba484f13d0f1988a3e5
2025-12-21 08:47:57 UTC to 2025-12-21 08:46:33 UTC

- docs(comments): improve readability and formatting (rust-lang/rust-by-example#1981)
- Fix HOF.MD sum of odd squares algorithm (rust-lang/rust-by-example#1980)