DEPR: Added is_copy to NDFrame._deprecations

[cbertinato]

Should have been part of PR #18801

[codecov]

Codecov Report

Merging #18922 into master will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #18922      +/-   ##
==========================================
+ Coverage   91.65%   91.67%   +0.01%     
==========================================
  Files         154      154              
  Lines       51368    51368              
==========================================
+ Hits        47080    47090      +10     
+ Misses       4288     4278      -10

Flag	Coverage Δ
#multiple	89.54% <ø> (+0.01%)	⬆️
#single	40.84% <ø> (ø)	⬆️

Impacted Files	Coverage Δ
pandas/core/generic.py	95.92% <ø> (ø)	⬆️
pandas/util/testing.py	84.68% <0%> (-0.22%)	⬇️
pandas/plotting/_converter.py	66.95% <0%> (+1.73%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6164da2...2c24813. Read the comment docs.

[jreback]

thanks @cbertinato