negative values for all DHT22 variants

[ssieb]

What does this implement/fix?

There appears to be a new variant of DHT22 with different negative value handling. This should cover all of them automatically.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Related issue or feature (if applicable): fixes esphome/issues#5322

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#

Test Environment

• ESP32
• ESP32 IDF
• ESP8266
• RP2040
• BK72xx
• RTL87xx

Example entry for config.yaml:

# Example config.yaml

Checklist:

• The code change is tested and works locally.
• Tests have been added to verify that the new code works (under tests/ folder).

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in esphome-docs.

[probot-esphome]

Hey there @OttoWinter, mind taking a look at this pull request as it has been labeled with an integration (dht) you are listed as a code owner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (4b783c0) 53.54% compared to head (a7c7c0f) 53.54%.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev    #6074   +/-   ##
=======================================
  Coverage   53.54%   53.54%           
=======================================
  Files          50       50           
  Lines        9374     9374           
  Branches     1650     1650           
=======================================
  Hits         5019     5019           
  Misses       4054     4054           
  Partials      301      301           

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