fix: add deploy and signing config to standalone BOM (#1720)

The BOM has no parent so it doesn't inherit distributionManagement,
nexus-staging-maven-plugin, or maven-gpg-plugin from the root POM.
Without these the publish step would fail to stage and sign the
artifact for Maven Central.

Signed-off-by: Javier Aliaga <javier@aliaga.dev>
Signed-off-by: Javier Aliaga <javier@diagrid.io>

Author: javier-aliaga

sdk-bom/pom.xml

@@ -35,7 +35,15 @@
     <tag>HEAD</tag>
   </scm>
 
+  <distributionManagement>
+    <snapshotRepository>
+      <id>ossrh</id>
+      <url>https://central.sonatype.com/repository/maven-snapshots/</url>
+    </snapshotRepository>
+  </distributionManagement>
+
   <properties>
+    <gpg.skip>true</gpg.skip>
     <dapr.sdk.version>1.18.0-SNAPSHOT</dapr.sdk.version>
     <!-- TODO: Remove netty-bom override once gRPC ships with Netty >= 4.1.132 (CVE-2026-33871, CVE-2026-33870) -->
     <netty.version>4.1.132.Final</netty.version>
@@ -44,6 +52,43 @@
     <commons-compress.version>1.26.0</commons-compress.version>
   </properties>
 
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.sonatype.plugins</groupId>
+        <artifactId>nexus-staging-maven-plugin</artifactId>
+        <version>1.7.0</version>
+        <extensions>true</extensions>
+        <configuration>
+          <serverId>ossrh</serverId>
+          <nexusUrl>https://ossrh-staging-api.central.sonatype.com</nexusUrl>
+          <autoReleaseAfterClose>true</autoReleaseAfterClose>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-gpg-plugin</artifactId>
+        <version>3.1.0</version>
+        <executions>
+          <execution>
+            <id>sign-artifacts</id>
+            <phase>verify</phase>
+            <goals>
+              <goal>sign</goal>
+            </goals>
+            <configuration>
+              <gpgArguments>
+                <arg>--batch</arg>
+                <arg>--pinentry-mode</arg>
+                <arg>loopback</arg>
+              </gpgArguments>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+
   <dependencyManagement>
     <dependencies>
       <!-- ====================================================================== -->