chore: update Gradle to 9.7.1 (#7673)

Automated update of the Gradle wrapper and Gradle Docker build images.

Gradle version: `9.7.1`
Docker image: `gradle:9.7.1-jdk25`

Co-authored-by: Frooodle <77850077+Frooodle@users.noreply.github.com>

Author: github-actions[bot]

docker/backend/Dockerfile

@@ -4,7 +4,7 @@ ARG BASE_VERSION=1.0.2@sha256:c7698687f486707ddef9e0298587ca8b44c4e96185e1bdb0c3
 ARG BASE_IMAGE=stirlingtools/stirling-pdf-base:${BASE_VERSION}
 
 # Stage 1: Build the Java application (backend only, no frontend)
-FROM gradle:9.7.1-jdk25@sha256:a80276ab804c348989df46016e2b5d58cad07c5b29e06f2112434d28ca5b2844 AS app-build
+FROM gradle:9.7.1-jdk25@sha256:d868117760a7c92214705f47ed173116a5d13e58d68702f974ff30acd062737e AS app-build
 
 # JDK 25+: --add-exports is no longer accepted via JAVA_TOOL_OPTIONS; use JDK_JAVA_OPTIONS instead
 ENV JDK_JAVA_OPTIONS="--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED \

docker/embedded/Dockerfile

@@ -5,7 +5,7 @@ ARG BASE_VERSION=1.0.2@sha256:c7698687f486707ddef9e0298587ca8b44c4e96185e1bdb0c3
 ARG BASE_IMAGE=stirlingtools/stirling-pdf-base:${BASE_VERSION}
 
 # Stage 1: Build the Java application and frontend
-FROM gradle:9.7.1-jdk25@sha256:a80276ab804c348989df46016e2b5d58cad07c5b29e06f2112434d28ca5b2844 AS app-build
+FROM gradle:9.7.1-jdk25@sha256:d868117760a7c92214705f47ed173116a5d13e58d68702f974ff30acd062737e AS app-build
 
 ARG TASK_VERSION=3.52.0
 RUN apt-get update \

docker/embedded/Dockerfile.fat

@@ -8,7 +8,7 @@ ARG BASE_VERSION=1.0.2@sha256:c7698687f486707ddef9e0298587ca8b44c4e96185e1bdb0c3
 ARG BASE_IMAGE=stirlingtools/stirling-pdf-base:${BASE_VERSION}
 
 # Stage 1: Build the Java application and frontend
-FROM gradle:9.7.1-jdk25@sha256:a80276ab804c348989df46016e2b5d58cad07c5b29e06f2112434d28ca5b2844 AS app-build
+FROM gradle:9.7.1-jdk25@sha256:d868117760a7c92214705f47ed173116a5d13e58d68702f974ff30acd062737e AS app-build
 
 ARG TASK_VERSION=3.52.0
 RUN apt-get update \

docker/embedded/Dockerfile.ultra-lite

@@ -4,7 +4,7 @@
 # Single JAR contains both frontend and backend with minimal dependencies
 
 # Stage 1: Build application with embedded frontend
-FROM gradle:9.7.1-jdk25@sha256:a80276ab804c348989df46016e2b5d58cad07c5b29e06f2112434d28ca5b2844 AS build
+FROM gradle:9.7.1-jdk25@sha256:d868117760a7c92214705f47ed173116a5d13e58d68702f974ff30acd062737e AS build
 
 # Install Node.js and npm for frontend build
 ARG TASK_VERSION=3.52.0