fix broken link in Action Cable guides and readme [ci skip]

When Content-Type is "application/x-gzip", request.content_type resolves to "application/gzip", because application/x-gzip is a synonym of application/gzip by default. This causes the acceptable_content? check in ActiveStorage::DiskController to fail, because the direct upload token contains application/x-gzip, which is not equal to application/gzip.

Fix by comparing the token content type with the request content type *and its synonyms*.

respect only_path option when an array is passed into url_for

Deprecate ActionDispatch::Http::ParameterFilter in favor of ActiveSup…

[ci skip] Fix typo

Fix an issue in ActiveStorage where a direct upload to disk storage
would fail due to a content type mismatch if the file was uploaded using
a mime-type synonym.

Since #31575, `set_inverse_instance` replaces the foreign key by the
current owner immediately to make it happen when a record is added to
collection association.

But `set_inverse_instance` is not only called when a record is added,
but also when a record is loaded from queries. And also, that loaded
records are not always associated records for some reason (using `or`,
`unscope`, `rewhere`, etc).

It is hard to distinguish whether or not we should invoke
`set_inverse_instance`, but at least we should avoid the undesired
side-effect which was brought from #31575.

Fixes #34108.

Fixtures refactor

getting started page rails version update to 5.2.1

add test for cache_version precision

ActiveStorage guide: Add instruction for test environment

Array with single item correctly uses cache_key

Remove "include FileUtils" sentence in setup/update bin files

Using `included` to define `attr_acessor` and `attr_writer` is causing
these methods to not show up in the documentation.

Add documentation to run tests with specific seed [ci skip]

Remove bundler warnings from bin/setup output

Parameterized mailers can configure delivery job

This commit documents how to run all tests or a single test file with a
specific randomization seed.

Remove some autolabeling globs

[ci skip]

Skip node_modules dir in the rubocop check