Merge branch 'tb/config-copy-or-rename-in-file-injection'

Avoids issues with renaming or deleting sections with long lines, where
configuration values may be interpreted as sections, leading to
configuration injection. Addresses CVE-2023-29007.

* tb/config-copy-or-rename-in-file-injection:
  config.c: disallow overly-long lines in `copy_or_rename_section_in_file()`
  config.c: avoid integer truncation in `copy_or_rename_section_in_file()`
  config: avoid fixed-sized buffer when renaming/deleting a section
  t1300: demonstrate failure when renaming sections with long lines

Signed-off-by: Taylor Blau <me@ttaylorr.com>