Unable to build project using latest version of gradle

Nobody has claimed this yet.

Error:
```
spedamallu@spedamallu-mbp143 ~/PersonalProjects/transport/transportable-udfs-examples (master) $
| => gradle build
Starting a Gradle Daemon (subsequent builds will be faster)

> Configure project :transport
Building version '0.0.62' (value loaded from 'version.properties' file).

FAILURE: Build failed with an exception.

* Where:
Build file '/Users/spedamallu/PersonalProjects/transport/build.gradle' line: 68

* What went wrong:
A problem occurred evaluating project ':transport:transportable-udfs-annotation-processor'.
> Failed to apply plugin 'org.gradle.java'.
> Could not find method testCompile() for arguments [org.testng:testng:6.11] on object of type org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

Deprecated Gradle features were used in this build, making it incompatible with Gradle 8.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/7.0/userguide/command_line_interface.html#sec:command_line_warnings

BUILD FAILED in 22s
```

Version:
```
spedamallu@spedamallu-mbp143 ~/PersonalProjects/transport (master) $
| => gradle --version

------------------------------------------------------------
Gradle 7.0
------------------------------------------------------------

Build time: 2021-04-09 22:27:31 UTC
Revision: d5661e3f0e07a8caff705f1badf79fb5df8022c4

Kotlin: 1.4.31
Groovy: 3.0.7
Ant: Apache Ant(TM) version 1.10.9 compiled on September 27 2020
JVM: 1.8.0_281 (Oracle Corporation 25.281-b09)
OS: Mac OS X 10.14.6 x86_64

spedamallu@spedamallu-mbp143 ~/PersonalProjects/transport (master) $
```

Issue seems to be because of deprecated configurations and renaming them in gradle7 - https://github.com/gradle/gradle/blob/c4d09af3db073776225e705307d93284df8753c0/subprojects/docs/src/docs/userguide/migration/upgrading_version_6.adoc#removal-of-compile-and-runtime-configurations

Would like to know if this was attempted already and was discouraged for any reason. Otherwise, happy to create a PR.

Start with build.gradle at line 68 and the transportable-udfs-annotation-processor project named in the error. Run gradle build with Gradle 7.0, inspect the testCompile dependency configuration, and compare it with the Gradle 7 migration guidance linked in the issue. Done means the project builds successfully with the reported Gradle version and its tests remain usable.

Written by the indexing model from the issue text.