replace usage of copy_arrays=True with memmap=False

[zacharyburnett]

follow-on to asdf-format/asdf#1797

Checklist for PR authors (skip items if you don't have permissions or they are not applicable)

• added entry in CHANGES.rst within the relevant release section
• updated or added relevant tests
• updated relevant documentation
• added relevant milestone
• added relevant label(s)
• ran regression tests, post a link to the Jenkins job below.
  How to run regression tests on a PR
• All comments are resolved
• Make sure the JIRA ticket is resolved properly

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 60.21%. Comparing base (8381431) to head (a2a4e3a).
Report is 6 commits behind head on master.

Files	Patch %	Lines
jwst/lib/set_telescope_pointing.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8660      +/-   ##
==========================================
- Coverage   60.23%   60.21%   -0.02%     
==========================================
  Files         370      370              
  Lines       38636    38630       -6     
==========================================
- Hits        23272    23261      -11     
- Misses      15364    15369       +5     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[zacharyburnett]

regtest: https://github.com/spacetelescope/RegressionTests/actions/runs/9994022959

[braingram]

LGTM.