Use Jenkins 2.263.1 as minimum Jenkins version

over 90% of users on last 4 releases are 2.263.1 or newer

pom.xml

@@ -30,7 +30,7 @@
     <gitHubRepo>jenkinsci/${project.artifactId}-plugin</gitHubRepo>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <argLine>-Dfile.encoding=${project.build.sourceEncoding}</argLine>
-    <jenkins.version>2.249.1</jenkins.version>
+    <jenkins.version>2.263.1</jenkins.version>
     <java.level>8</java.level>
     <no-test-jar>false</no-test-jar>
     <useBeta>true</useBeta>
@@ -287,7 +287,7 @@
     <dependencies>
       <dependency>
         <groupId>io.jenkins.tools.bom</groupId>
-        <artifactId>bom-2.249.x</artifactId>
+        <artifactId>bom-2.263.x</artifactId>
         <version>26</version>
         <scope>import</scope>
         <type>pom</type>