chore(python): remove obsolete release scripts and config files (#755)

* chore(python): remove obsolete release scripts and config files

Source-Link: https://github.com/googleapis/synthtool/commit/635751753776b1a7cabd4dcaa48013a96274372d
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:91d0075c6f2fd6a073a06168feee19fa2a8507692f2519a1dc7de3366d157e99

* See https://github.com/googleapis/synthtool/pull/2035

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Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Anthonios Partheniou <partheniou@google.com>
8 files changed