[wanda] add `disable_caching` option (#305)

allows running a wanda build without caching enabled. this helps on
building images which contents are fast to build but changing
frequently. if these images are cached, it can spam the container
registry and make the registry run out of image count quota if it is an
ECR.

Signed-off-by: Lonnie Liu <lonnie@anyscale.com>

[wanda] add hints args that are not calculated in build input (#302)

`build_hint_args` are build args that will not be captured in the build
input.
this allows sending in configs that are unrelated to the build result,
such
as caching configs, but can still allow the build output to be cached
properly.

[wanda] add filepath.FromSlash to properly handle slashes (#297)

so that it works properly in the case of windows systems

remove trainium queue, add g6 queue (#291)

required for running more modern llm workloads

Signed-off-by: Lonnie Liu <lonnie@anyscale.com>

[rayci] also pass in `BUILDKITE_SOURCE` (#288)

can be used detect if it is auto or manual

[rayci] mention the right step type in error message (#281)

so that it is not always "wait" type.

[rayci] support generic '.ci.yaml' suffixes (#277)

so that repo using the tool does not have to mention ray

fix bugs in aws role assuming (#276)

- it is "propagate" rather than "propogate
- and the duration needs to be an integer

[rayci] add aws assume role support (#275)

so that we can use rayci to run a job that assumes into another role

[ci] add block for apple silicon test (#273)

the test does not run much, but often needs to wait for a long time

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Signed-off-by: Lonnie Liu <lonnie@anyscale.com>