audit: correct inverted has_trailing_newline condition

has_trailing_newline? checked if formula did not have a trailing
newline. Invert regex and invert audit check.

Closes #18359.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
Index pkgconfig directories by MacOS.version
Exclude global pkgconfig dirs under superenv
bottles: remove unused 'version' from DSL.
Warn on bottles skipped due to non-default Cellar.

Closes #18333.
Add pkgconfig dirs for all deps under superenv

Fixes #18367.
Rename these collections for clarity
Use attr_accessor to suppress warning
Fix tests under 32-bit SL
Adjust BOTTLE_EXTNAME_RX for :snow_leopard_32
tests: allow setting MACOS_VERSION from the environment

This makes it easy to test things that vary depending on this constant
without editing testing_env.rb.