Add interleaved pp support (#6498)

* Add support for Virtual Pipeline Parallel conversion

Signed-off-by: smajumdar <[email protected]>

* Add support for Virtual Pipeline Parallel conversion

Signed-off-by: smajumdar <[email protected]>

* Switch to megatron core

Signed-off-by: smajumdar <[email protected]>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

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Signed-off-by: smajumdar <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
(cherry picked from commit 8929871)