Remove binlog-server point in time recoveries code & tests

[shlomi-noach]

Description

This PR removes the legacy code for (Ripple) binlog-server based point in time recoveries. That code is unsupported since v17.

TBD: clarify in website docs that the feature is removed (right now it says "legacy", see https://vitess.io/docs/22.0/reference/features/recovery/#point-in-time-recovery-legacy-functionality-based-on-binlog-server)

Docs: vitessio/website#1902. Just completely strip out the legacy docs.

Related Issue(s)

Closes #16673

Checklist

• "Backport to:" labels have been added if this change should be back-ported to release branches
• If this change is to be back-ported to previous releases, a justification is included in the PR description
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on CI?
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

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[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 67.50%. Comparing base (0d84a49) to head (ae458a7).
Report is 15 commits behind head on main.

Files with missing lines	Patch %	Lines
go/mysql/flavor_filepos.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #17361      +/-   ##
==========================================
+ Coverage   67.46%   67.50%   +0.04%     
==========================================
  Files        1581     1581              
  Lines      253934   253774     -160     
==========================================
+ Hits       171305   171306       +1     
+ Misses      82629    82468     -161     

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[dbussink]

Should test/bin/rippled also be removed?

[shlomi-noach]

Should test/bin/rippled also be removed?

Good catch, removed.

[mattlord]

Curious why we need the directory?

[shlomi-noach]

The mysql_server_vault CI job downloads the vault binary onto this directory. That CI fails when the directory does not exist.