Fix Gradle build so you don't have to have Git

.github/workflows/gradle.yml

@@ -12,4 +12,4 @@ jobs:
         with:
           java-version: 17
       - name: Build with Gradle
-        run: chmod a+x gradlew && ./gradlew build -x buildProperties
+        run: chmod a+x gradlew && ./gradlew build

build.gradle

@@ -3,6 +3,7 @@ plugins {
     id 'maven-publish'
     id 'idea'
     id 'checkstyle'
+    id "xyz.ronella.simple-git" version "1.3.0"
     id 'com.github.johnrengelman.shadow' version '7.0.0'
     id 'net.minecrell.plugin-yml.bukkit' version '0.5.0'
 }
@@ -99,7 +100,7 @@ dependencies {
     implementation('io.papermc:paperlib:1.0.6')
     implementation('org.bstats:bstats-base:2.2.1')
     implementation('org.bstats:bstats-bukkit:2.2.1')
-    implementation('org.reflections:reflections:0.9.12')
+    implementation('org.reflections:reflections:0.10.1')
     implementation('org.javassist:javassist:3.28.0-GA')
     implementation('org.jetbrains:annotations:22.0.0')
     implementation('com.mattmalec:Pterodactyl4J:2.BETA_80')
@@ -139,22 +140,32 @@ static def getDate() {
     return new Date().format('MM/dd/yyyy HH:mm')
 }
 
-def getGitHash() {
+String getGitHash() {
     def stdout = new ByteArrayOutputStream()
-    exec {
-        commandLine 'git', 'rev-parse', '--short', 'HEAD'
-        standardOutput = stdout
+    try {
+        exec {
+            commandLine "git", "rev-parse", "--short", "HEAD"
+            standardOutput = stdout
+            ignoreExitValue = true
+        }
+    } catch (GradleException e) {
+        logger.error("Couldn't determine Git head because Git is not installed. " + e.getMessage())
     }
-    return stdout.toString().trim()
+    return stdout.size() > 0 ? stdout.toString().trim() : "unknown"
 }
 
-def getBuildNumber() {
+String getBuildNumber() {
     def stdout = new ByteArrayOutputStream()
-    exec {
-        commandLine 'git', 'rev-list', 'HEAD', '--count'
-        standardOutput = stdout
+    try {
+        exec {
+            commandLine "git", "rev-list", "HEAD", "--count"
+            standardOutput = stdout
+            ignoreExitValue = true
+        }
+    } catch (GradleException e) {
+        logger.error("Couldn't determine Git head because Git is not installed. " + e.getMessage())
     }
-    return stdout.toString().trim()
+    return stdout.size() > 0 ? stdout.toString().trim() : "unknown"
 }
 
 tasks.withType(Checkstyle) {