Fix broken release flow/ update RSA SSH Host key

[jeetchoudhary]

The current release flow is broken https://github.com/salesforce/dockerfile-image-update/actions/runs/5264390864
because GitHub updated its RSA SSH host key on March 24, 2023.

GitHub's SSH key fingerprints: https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/githubs-ssh-key-fingerprints
GitHub's announcement: https://github.blog/2023-03-23-we-updated-our-rsa-ssh-host-key/

[codecov]

Codecov Report

Merging #986 (54c5083) into main (68e6d18) will not change coverage.
The diff coverage is n/a.

❗ Current head 54c5083 differs from pull request most recent head 0105a57. Consider uploading reports for the commit 0105a57 to get more accurate results

@@            Coverage Diff            @@
##               main     #986   +/-   ##
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  Coverage     84.62%   84.62%           
  Complexity      378      378           
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  Files            27       27           
  Lines          1255     1255           
  Branches        166      166           
=========================================
  Hits           1062     1062           
  Misses          157      157           
  Partials         36       36