refactor: remove duplicate null checks (#821)

# Motivation

- Simplify the codebase by removing duplicate checks that were already
performed earlier in the logic

# Description

- Removed two **if** statements checking for null values.
- These conditions were confirmed to be already validated in the
execution flow.
- No changes to the functionality.

# Testing

- Logic wasn't changed in tests in the CI passed.

# Impact

- No impact on functionality as the redundant checks were unnecessary.

# Additional Information

- None

# Checklist

- [x] My code adheres to the coding and style guidelines of the project.
- [x] I have performed a self-review of my code.
- [x] I have commented my code, particularly in hard-to-understand
areas.
- [x] I have made corresponding changes to the documentation.
- [x] I have thoroughly tested my modifications and added tests when
necessary.
- [x] Tests pass locally and in the CI.
- [x] I have assessed the performance impact of my modifications.

Utils/src/ServerCertificateValidator.cs

@@ -58,18 +58,6 @@ public static RemoteCertificateValidationCallback ValidationCallback(ILogger
            return false;
          }
 
-         if (certificate == null)
-         {
-           logger.LogDebug("Certificate is null!");
-           return false;
-         }
-
-         if (chain == null)
-         {
-           logger.LogDebug("Certificate chain is null!");
-           return false;
-         }
-
          // If there is any error other than untrusted root or partial chain, fail the validation
          if (chain.ChainStatus.Any(status => status.Status is not X509ChainStatusFlags.UntrustedRoot and not X509ChainStatusFlags.PartialChain))
          {