drop gradle support before 7.3

debian bookworm supports only Java 17+, which is compatible with gradle 7.3+: https://docs.gradle.org/current/userguide/compatibility.html

tests/test-gradlew-fdroid

@@ -56,7 +56,7 @@ run_test osmandapp/osmand 2.2.1
 cd $tmpdir
 mkdir -p download_cache_test/gradle/wrapper
 cd download_cache_test
-echo 'distributionUrl=https\://services.gradle.org/distributions/gradle-2.0-bin.zip' \
+echo 'distributionUrl=https\://services.gradle.org/distributions/gradle-5.0-bin.zip' \
      > gradle/wrapper/gradle-wrapper.properties
 printf "task helloWorld {\n\tdoLast {\n\t\tprintln '$TEST_VALUE'\n\t}\n}" > build.gradle
 
@@ -65,11 +65,11 @@ mkdir -p $GRADLE_VERSION_DIR
 
 unset https_proxy
 printf "download, unpack, and run: "
-download_cache_test 2.0
+download_cache_test 5.0
 printf "unpack and run: "
-rm -rf $GRADLE_VERSION_DIR/2.0/
-download_cache_test 2.0
+rm -rf $GRADLE_VERSION_DIR/5.0/
+download_cache_test 5.0
 printf "just run: "
-download_cache_test 2.0
+download_cache_test 5.0
 
 exit $exit_value

tests/triple-t-anysoftkeyboard/metadata/com.anysoftkeyboard.languagepack.dutch.yml

@@ -53,7 +53,7 @@ Builds:
     subdir: addons/languages/dutch
     sudo:
       - apt-get update || apt-get update
-      - apt-get install -t stretch-backports openjdk-11-jdk-headless openjdk-11-jre-headless
+      - apt-get install -t sid-backports openjdk-11-jdk-headless openjdk-11-jre-headless
       - update-alternatives --auto java
     gradle:
       - yes

tests/triple-t-anysoftkeyboard/metadata/com.menny.android.anysoftkeyboard.yml

@@ -499,7 +499,7 @@ Builds:
     subdir: ime/app
     sudo:
       - apt-get update || apt-get update
-      - apt-get install -t stretch-backports openjdk-11-jdk-headless openjdk-11-jre-headless
+      - apt-get install -t sid-backports openjdk-11-jdk-headless openjdk-11-jre-headless
       - update-alternatives --auto java
     gradle:
       - yes