Remove unnecessary SDE resampling in PPO update

[brn-dev]

Description

Remove policy.reset_noise() call in PPO update

Motivation and Context

Resampling the SDE noise in the PPO update is unnecessary, for more info see #1929

• I have raised an issue to propose this change (required for new features and bug fixes)

closes #1929

Types of changes

• Bug fix (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 change)
• Documentation (update in the documentation)

Checklist

• I've read the CONTRIBUTION guide (required)
• I have updated the changelog accordingly (required).
• My change requires a change to the documentation.
• I have updated the tests accordingly (required for a bug fix or a new feature).
• I have updated the documentation accordingly.
• I have opened an associated PR on the SB3-Contrib repository (if necessary)
• I have opened an associated PR on the RL-Zoo3 repository (if necessary)
• I have reformatted the code using make format (required)
• I have checked the codestyle using make check-codestyle and make lint (required)
• I have ensured make pytest and make type both pass. (required)
• I have checked that the documentation builds using make doc (required)

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[araffin]

Thanks for the PR =)
could you do the same for PPO variants in SB3 contrib?

[araffin]

I've created a report to check that it had no impact on the performance (it changes results because the state of the pseudo-random generator is not the same but should not impact performance):
https://wandb.ai/openrlbenchmark/sb3/reports/PR-1933-Remove-gSDE-resampling--Vmlldzo4NDk4Nzgx

[araffin]

LGTM, thanks =)