This test was verifying that DockerProvider.Config() returned a
non-nil value, but Config() does not return a pointer, so it
would always pass (even with an empty struct).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

The TestcontainersConfig.RyukDisabled field is deprecated.
NewDockerProvider() uses ReadConfig() internally to load the config,
which always copies its value from config.Config.RyukDisabled field,
which is not deprecated.

This patch removes the extra redirection, and changes the code to
use Config.RyukDisabled instead.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

All fields in TestcontainersConfig are deprecated, making it a
wrapper around config.Config and DockerProvider internally only
depends on config.Config. All deprecated fields contain a copy
of values available in config.Config.

However, the exported `Config()` has TestcontainersConfig as return type;
filling the deprecated fields is is currently handled by ReadConfig, but
straightforward, so we can inline that code in the `Config()` method.

This patch:

- changes the (non-exported) config field to hold a config.Config (which
  provides all the data used).
- removes internal uses of the `Config()` method; the `Config()` method
  did not provide value for internal use; the `config` field is not mutated
  (so no synchronisation needed for concurrency).
- updates the `Config()` method to handle conversion of the config.Config
  to a `TestcontainersConfig` (effectively inlining a copy of `ReadConfig`)

After this patch, the only remaining use of `ReadConfig` in testcontainers-go
itself is in tests (`TestReadConfig`); as a follow-up, we can consider
deprecating `ReadConfig` and `TestcontainersConfig`, although `DockerProvider`
may need a new `Config()` method with a different signature if its config
must be accessible for others, which would require the `ContainerProvider`
and `ReaperProvider` interfaces to be updated.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

* main:
  fix: never cache JSON representation of a container (#2606)
  chore: remove most uses of  TestcontainersConfig and deprecated TestcontainersConfig fields. (#2614)
  chore(deps): bump github.com/docker/docker from v27.0.2 to v27.0.3 (#2615)
  chore(deps): bump github.com/docker/docker from v26.1.4 to v27.0.2 (#2593)