Merge bitcoindevkit/bdk#2001: ci: fix `socket2` pin

5ebbac83ee2dcf50011976d55e0446d9f23780f8 ci: fix `socket2` pin (Wei Chen)

Pull request description:

  ### Description

  Fix `socket2` pin that was causing CI issues.

  ### Changelog notice

  * Unpinned `socket2` dependency that was causing CI issues.

  ### Checklists

  #### All Submissions:

  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)

ACKs for top commit:
  oleonardolima:
    ACK 5ebbac83ee2dcf50011976d55e0446d9f23780f8
  notmandatory:
    ACK 5ebbac83ee2dcf50011976d55e0446d9f23780f8

Tree-SHA512: f5b59fb0f8489f136f4e817de72a728a785e4e4803624143f90d35a70cba9cc4b0185c1fa3fcc42132cccd7bc4b80d7b7d8469e1c172b68e790dfe1af253ac7b