BUG: DataFrame/Series constructor with tz aware data and datetime64[ns] dtype converts to naive

[mroeschke]

• closes DataFrame (and Series?) constructor ignores request for naive datetime64 dtype when passed datetime64 objects with timezone #25843
• tests added / passed
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

[codecov]

Codecov Report

Merging #26167 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master   #26167      +/-   ##
==========================================
- Coverage   91.98%   91.97%   -0.01%     
==========================================
  Files         175      175              
  Lines       52377    52380       +3     
==========================================
- Hits        48180    48179       -1     
- Misses       4197     4201       +4

Flag	Coverage Δ
#multiple	90.53% <100%> (ø)	⬆️
#single	40.71% <75%> (-0.15%)	⬇️

Impacted Files	Coverage Δ
pandas/core/dtypes/cast.py	91.54% <100%> (+0.04%)	⬆️
pandas/io/gbq.py	78.94% <0%> (-10.53%)	⬇️
pandas/core/frame.py	96.9% <0%> (-0.12%)	⬇️

---

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 dc86509...b6b3049. Read the comment docs.

[codecov]

Codecov Report

Merging #26167 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master   #26167      +/-   ##
==========================================
- Coverage   91.98%   91.97%   -0.01%     
==========================================
  Files         175      175              
  Lines       52377    52380       +3     
==========================================
- Hits        48180    48179       -1     
- Misses       4197     4201       +4

Flag	Coverage Δ
#multiple	90.53% <100%> (ø)	⬆️
#single	40.71% <75%> (-0.15%)	⬇️

Impacted Files	Coverage Δ
pandas/core/dtypes/cast.py	91.54% <100%> (+0.04%)	⬆️
pandas/io/gbq.py	78.94% <0%> (-10.53%)	⬇️
pandas/core/frame.py	96.9% <0%> (-0.12%)	⬇️

---

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 dc86509...b6b3049. Read the comment docs.

[jreback]

thanks @mroeschke