install testcontainers from jitpack

the method signature of `ChromeOptions#addArguments` has changed:
testcontainers/testcontainers-java#4593 (comment)

until testcontainers/testcontainers-java#4609 is
merged and released, testcontainers artifacts should be installed from
jitpack instead of maven so that changes in this open pull request are
included.

build.gradle

@@ -87,12 +87,15 @@ dependencies {
     implementation 'com.github.jkatzwinkel:tla-common:main-SNAPSHOT'
     implementation 'com.github.rosmord.jsesh:jsesh:release-7.5.5'
 
-    testImplementation 'org.seleniumhq.selenium:selenium-remote-driver:4.1.0'
-    testImplementation 'org.seleniumhq.selenium:selenium-chrome-driver:4.1.0'
-    testImplementation 'org.seleniumhq.selenium:selenium-support:4.1.0'
-    testImplementation 'org.testcontainers:selenium:1.16.2'
-    testImplementation 'org.testcontainers:junit-jupiter:1.16.2'
-    testImplementation 'org.springframework.boot:spring-boot-starter-test:2.6.1'
+    testImplementation 'org.seleniumhq.selenium:selenium-remote-driver:4.1.1'
+    testImplementation 'org.seleniumhq.selenium:selenium-chrome-driver:4.1.1'
+    testImplementation 'org.seleniumhq.selenium:selenium-support:4.1.1'
+    // can be changed back to maven central (org.testcontainers) once
+    // https://github.com/testcontainers/testcontainers-java/pull/4609
+    // is merged:
+    testImplementation 'com.github.testcontainers.testcontainers-java:selenium:selenium-refactoring-SNAPSHOT'
+    testImplementation 'com.github.testcontainers.testcontainers-java:junit-jupiter:selenium-refactoring-SNAPSHOT'
+    testImplementation 'org.springframework.boot:spring-boot-starter-test:2.6.2'
     testImplementation 'org.junit.jupiter:junit-jupiter-params:5.8.2'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.2'
 }