Glue: honour HidePassword on get_connection and get_connections

[chiruu12]

Fixes #10251

HidePassword reached the backend and was then ignored, so asking for a connection without its secret returned the secret.

as_dict now takes the flag and drops the PASSWORD entry, which is what AWS does rather than blanking the value. Both copies are redacted: the top level ConnectionProperties and the nested Connection, which carries the same dict.

The redaction happens on the way out, so the stored connection keeps its password and a later call without the flag still returns it.

I also dropped hide_password from the two backend signatures. With the redaction in as_dict nothing in the backend reads it, and leaving a parameter that is never looked at is what caused this in the first place.

Four tests. Two fail on the parent commit; the other two pin that the default still returns the password and that hiding it does not change what is stored.

tests/test_glue/: 296 passed, with ruff format --check and mypy clean. ruff check reports 7 findings under moto/glue/; the same 7 are on master and none are in this change.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.33%. Comparing base (289555e) to head (0f0275f).
⚠️ Report is 22 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #10252      +/-   ##
==========================================
+ Coverage   93.32%   93.33%   +0.01%     
==========================================
  Files        1342     1342              
  Lines      122702   122925     +223     
==========================================
+ Hits       114508   114736     +228     
+ Misses       8194     8189       -5     

Flag	Coverage Δ
servertests	27.91% <7.14%> (-0.03%)	⬇️
unittests	93.31% <100.00%> (+0.01%)	⬆️

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