Removes temporary rollout toggle ENABLE_SAML_CONFIG_SIGNAL_HANDLERS. The
toggle was used to rollout a fix, and now the fix that uses the signal handlers is
enabled by default.
The only follow-up needed by anyone is to no longer set this toggle, which will no
longer do anything.
Introduces temporary rollout toggle ENABLE_SAML_CONFIG_SIGNAL_HANDLERS
which controls whether SAML configuration signal handlers are active.
When enabled (True), signal handlers will automatically update SAMLProviderConfig
references when the associated SAMLConfiguration is updated.
When disabled (False), SAMLProviderConfigs point to outdated SAMLConfiguration.
Warning: Disabling this toggle may result in SAMLProviderConfig instances
pointing to outdated SAMLConfiguration records.
Use the management command 'saml --fix-references' to fix outdated references.
