DEV-1013 Align every Gradle wrapper on 8.14.3

The committed ShimmerDriver wrapper was pinned to 6.1 and could not resolve
its own dependencies: io.grpc:grpc-all:1.71.0 pulls Guava 33.3.1 transitively
and requests both the -jre and -android flavours, which are told apart by the
org.gradle.jvm.environment attribute that Gradle 7.0 introduced. 6.1 does not
know that attribute, cannot disambiguate, and fails. Nothing about our code is
wrong - the dependency graph moved underneath an old wrapper.

CI never caught it because it installed Gradle 8.10.2 and never invoked
./gradlew, so `cd ShimmerDriver && ./gradlew test` failed for developers while
CI stayed green.

8.14.3 matches ASM_PC, which already builds and tests this exact source with it.

Every module's wrapper is now the same 8.14.3 distribution, so the whole repo
shares one Gradle. Previously: ShimmerDriver, ShimmerBluetoothManager,
ShimmerTCP, ShimmerPCBasicExamples and JavaShimmerConnect on 6.1,
ShimmerDriverPC on 8.10, ShimmerLSL on 2.14.1 (which cannot even parse a JDK 11
version string).

gradlew also gains the executable bit. It was committed 100644, which is why
the workflow carried a commented-out `chmod +x` step.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: marknolan

JavaShimmerConnect/gradle/wrapper/gradle-wrapper.jar

@@ -1,6 +1,7 @@
-#Wed Oct 05 15:40:57 BST 2016
-distributionBase=GRADLE_USER_HOME
-distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
-zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.1-bin.zip
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-all.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists