🌐 [translation-sync] Improve clarity and fix errors in Numba lecture (#101)

Syncs translation of lectures/numba.md with upstream source PR #524.

Changes include:
- Rename anchor (speed) to (numba_lecture)
- Remove Julia from vectorization weaknesses list
- Update performance comparison wording
- Fix Julia comparison text (correct casing, wording)
- Replace Decorator Notation section with admonition block
- Simplify type inference example (iterate/g instead of bootstrap/mean)
- Remove outdated nopython mode note
- Add global variables workaround advice
- Update multithreading section
- Remove duplicate import
- Add GPU parallelization cross-reference to JAX lectures

Source: QuantEcon/lecture-python-programming#524

Author: mmcky

.translate/state/numba.md.yml

@@ -1,6 +1,6 @@
-source-sha: 21f1ea0669031ccc0ee0194878439a87de5d248d
-synced-at: "2026-04-10"
+source-sha: a897eb875ecbf8975872fd6bc0a6b2e91a6ba701
+synced-at: "2026-04-12"
 model: claude-sonnet-4-6
 mode: UPDATE
-section-count: 7
+section-count: 6
 tool-version: 0.14.1