Add 1.3.1 release notes

[cliu123]

Description

• Category (Enhancement, New feature, Bug fix, Test fix, Refactoring, Maintenance, Documentation) Maintenance
• Why these changes are required? 1.3.1 release

Testing

UTs

Check List

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[codecov-commenter]

Codecov Report

Merging #1713 (b029c84) into 1.3 (c18a50a) will decrease coverage by 0.23%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##                1.3    #1713      +/-   ##
============================================
- Coverage     64.63%   64.40%   -0.24%     
+ Complexity     3221     3218       -3     
============================================
  Files           247      247              
  Lines         17358    17349       -9     
  Branches       3085     3071      -14     
============================================
- Hits          11219    11173      -46     
- Misses         4590     4626      +36     
- Partials       1549     1550       +1     

Impacted Files	Coverage Δ
...ava/com/amazon/dlic/auth/ldap2/MakeJava9Happy.java	8.69% <0.00%> (-34.79%)	⬇️
...com/amazon/dlic/auth/ldap2/PrivilegedProvider.java	44.26% <0.00%> (-6.56%)	⬇️
...ic/auth/ldap/backend/LDAPAuthorizationBackend.java	53.59% <0.00%> (-4.36%)	⬇️
...ecurity/configuration/ConfigurationRepository.java	73.07% <0.00%> (-2.20%)	⬇️
.../org/opensearch/security/support/ConfigHelper.java	80.39% <0.00%> (-1.97%)	⬇️
...zon/dlic/auth/ldap2/LDAPAuthorizationBackend2.java	28.35% <0.00%> (-0.38%)	⬇️
...dlic/auth/http/saml/AuthTokenProcessorHandler.java	46.99% <0.00%> (-0.29%)	⬇️
...ch/security/securityconf/DynamicConfigFactory.java	60.92% <0.00%> (-0.26%)	⬇️
...earch/security/resolver/IndexResolverReplacer.java	63.52% <0.00%> (-0.11%)	⬇️
.../org/opensearch/security/auth/BackendRegistry.java	59.26% <0.00%> (-0.11%)	⬇️
... and 4 more

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