try unlocking keychain

.github/scripts/ios/build.ps1

@@ -4,6 +4,10 @@
   [string] $platform = "iPhone"
 )
 
+security default-keychain -s build.keychain
+security unlock-keychain -p $env:KEYCHAIN_PASSWORD build.keychain
+security set-key-partition-list -S apple-tool:,apple: -s -k $env:KEYCHAIN_PASSWORD build.keychain
+
 $rootPath = $env:GITHUB_WORKSPACE;
 $iosPath = $($rootPath + "/src/iOS/iOS.csproj");
 

.github/workflows/build.yml

@@ -158,3 +158,5 @@ jobs:
       - name: Build for App Store
         run: ./.github/scripts/ios/build.ps1 -configuration AppStore -platform iPhone
         shell: pwsh
+        env:
+          KEYCHAIN_PASSWORD: ${{ secrets.IOS_KEYCHAIN_PASSWORD }}