Package updates; run tests against EF Core 7

[bkoelman]

In addition to minor package updates, this PR makes tests run against EF Core 7.
All code still targets .NET 6, and JsonApiDotNetCore itself still references EF Core 6, so this is a non-breaking change.

Closes #1212.

QUALITY CHECKLIST

• Changes implemented in code
• Complies with our contributing guidelines
• Adapted tests
• N/A: Documentation updated

[codecov]

Codecov Report

Merging #1249 (fa5ff77) into master (c7e396d) will not change coverage.
The diff coverage is 100.00%.

❗ Current head fa5ff77 differs from pull request most recent head ab8759c. Consider uploading reports for the commit ab8759c to get more accurate results

@@           Coverage Diff           @@
##           master    #1249   +/-   ##
=======================================
  Coverage   92.62%   92.62%           
=======================================
  Files         243      243           
  Lines        7795     7795           
=======================================
  Hits         7220     7220           
  Misses        575      575           

Impacted Files	Coverage Δ
src/Examples/NoEntityFrameworkExample/Program.cs	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.