Avo 1.x Backport: Rails 7 deprecates Date#to_s in favor of Date#to_formatted_s

[rickychilcott]

Description

Backport #774 to 1.x

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature work

[codecov]

Codecov Report

Merging #775 (47be8fa) into 1.x (9b59b00) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##              1.x     #775   +/-   ##
=======================================
  Coverage   94.28%   94.28%           
=======================================
  Files         375      375           
  Lines        6997     6997           
=======================================
  Hits         6597     6597           
  Misses        400      400           

Impacted Files	Coverage Δ
lib/avo/fields/date_field.rb	94.44% <0.00%> (ø)

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[adrianthedev]

Thank you!

I'm AFK now, but I'll cut a release Monday first thing.

Thanks for your contribution!