update to remove dependencies that are needed by tests

[cdeepali]

Checklist before submitting

• [x] Did you read the contributor guide?
• [ ] Did you update any affected documentation?
• [ ] Did you write any tests to validate this change?

Description

Fixes https://github.com/open-ce/pytorch-feedstock/issues/45.

Review process to land

1. All tests and other checks must succeed.
2. At least one maintainer must review and approve.
3. If any maintainer requests changes, they must be addressed.

[cdeepali]

Removed the following from run time dependencies:

• ninja - is required for cpp extension tests - https://github.com/pytorch/pytorch/blob/v1.8.0/test/run_test.py#L324. These tests are not run currently in open-ce-tests.yaml.
• numba - is required for numba_integration tests so added this to open-ce-tests.yaml
• python-lmdb - was required by some caffe2 tests. These tests are not run currently in open-ce-tests.yaml

Also removed absl-py as it is not a direct requirement for pytorch, it is needed by tensorboard and is a dependency there. https://github.com/open-ce/tensorboard-feedstock/blob/main/recipe/meta.yaml#L34