Removed larryosterman from attestation codeowners. (Azure#23782)

Author: LarryOsterman

.github/CODEOWNERS

@@ -41,7 +41,7 @@
 /sdk/applicationinsights/azure-applicationinsights/                  @omziv @anatse @raronen @ischrei @danhadari @azmonapplicationinsights
 /sdk/loganalytics/azure-loganalytics/                                @omziv @anatse @raronen @ischrei @danhadari @azmonapplicationinsights
 
-/sdk/attestation/azure-security-attestation                          @larryosterman @anilba06 @Azure/azure-sdk-write-attestation
+/sdk/attestation/azure-security-attestation                          @anilba06 @Azure/azure-sdk-write-attestation @gkostal
 
 # PRLabel: %Batch
 /sdk/batch/                                                          @cRui861 @paterasMSFT @dpwatrous @gingi @zfengms