gh-154753: docs: update references to moved files - #155553

Summary

Update documentation references to reflect files that have moved to their current locations in the CPython source tree.

The changes include:

• Update Android testbed and README references to Platforms/Android/.
• Update iOS documentation references to Platforms/Apple/.
• Update the iOS configuration documentation to reference Platforms/Apple/iOS/README.md.
• Update the Capsules implementation reference from Objects/pycapsule.c to Objects/capsule.c.
• Update the code object documentation reference from the removed Objects/lnotab_notes.txt to InternalDocs/code_objects.md.
• Fix the malformed Markdown link for codeobject.co_positions.
• Remove the broken link to the generated jit_stencils.h file.

Tests

• git diff --cached --check — passed
• Targeted pre-commit checks — passed
• make -C Doc html SPHINXOPTS="-j1" — completed with one pre-existing duplicate-label warning in Doc/using/windows.rst and Doc/reference/datamodel.rst.

Closes issue gh-154753