chore: remove graalvm 22.1 testing (#877)

Author: meltsufin

.github/workflows/downstream-native-image.yaml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        graalvm: [22.2.0, 22.1.0]
+        graalvm: [22.2.0]
         java: [11, 17]
         repo:
           # GAPIC library that doesn't use a real GCP project in integration tests
@@ -38,4 +38,4 @@ jobs:
       - run: java -version
       - run: sudo apt-get update -y
       - run: sudo apt-get install libxml2-utils
-      - run: .kokoro/downstream-client-library-check.sh ${{matrix.repo}} graalvm
+      - run: .kokoro/downstream-client-library-check.sh ${{matrix.repo}} graalvm