Docs: Remove FIPS 140 remarks from PATs/PrATs/GATs

What does this MR do?

We no longer disable PAT creation and use in FIPS mode, since PATs are not in the scope of FIPS 140. Instead we offer the ability to disable PATs meet FedRAMP or other compliance controls. Existing statements that PATs aren't FIPS-compliant or are disabled in FIPS mode are no longer accurate.

See Slack thread (team members only).

Related issues

Relates to Disable All Types of Access Tokens for FIPS-ena... (#351350 - closed) and Update FedRamp PAT creation to be an Applicatio... (#384201 - closed)

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