chore: Add java 8 to test matrix (#2034)

migrating to flint allows us to get around some limitations we had due
to the dependency on spotless, so now we can run our java compatibility
integration tests on java 8 🎉

Signed-off-by: Jay DeLuca <jaydeluca4@gmail.com>

Author: jaydeluca

.github/workflows/java-version-matrix-tests.yml

@@ -23,7 +23,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java-version: [11, 17, 21, 25]
+        java-version: [8, 11, 17, 21, 25]
     steps:
       - name: Check out
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -56,8 +56,8 @@ jobs:
       - name: Rebuild sample apps targeting Java ${{ matrix.java-version }}
         run: |
           cd integration-tests
-          # Note: Jetty 12 and Tomcat 11 require Java 17+, so servlet samples are skipped for Java 11
-          if [ "${{ matrix.java-version }}" = "11" ]; then
+          # Note: Jetty 12 and Tomcat 11 require Java 17+, so servlet samples are skipped for Java 8 & 11
+          if [[ "${{ matrix.java-version }}" == "11" || "${{ matrix.java-version }}" == "8" ]]; then
             MODULES="it-common,it-exporter/it-exporter-httpserver-sample,it-exporter/it-exporter-no-protobuf,it-pushgateway"
           else
             MODULES="it-common,it-exporter/it-exporter-httpserver-sample,it-exporter/it-exporter-servlet-tomcat-sample,it-exporter/it-exporter-servlet-jetty-sample,it-exporter/it-exporter-no-protobuf,it-pushgateway"
@@ -73,7 +73,7 @@ jobs:
         run: |
           cd integration-tests
           # Note: Servlet tests require Java 17+ (due to Jetty 12 and Tomcat 11)
-          if [ "${{ matrix.java-version }}" = "11" ]; then
+          if [[ "${{ matrix.java-version }}" == "11" || "${{ matrix.java-version }}" == "8" ]]; then
             TEST_MODULES="it-exporter/it-no-protobuf-test,it-pushgateway"
           else
             TEST_MODULES="it-exporter/it-exporter-test,it-exporter/it-no-protobuf-test,it-pushgateway"