Try that

.forgejo/workflows/build.yml

@@ -19,10 +19,10 @@ jobs:
         run: mkdir artifact && mvn clean package && mv target/tweaks-*+1.21.1.jar artifact/
 
       - name: Build for 1.21.3
-        run: find src \( -type d -name .git -prune \) -o -type f -print0 | xargs -0 sed -i "s/v1_21_R1/v1_21_R2/g" && mvn clean package -Dproject.minecraft.version=1.21.3 && mv target/tweaks-*+1.21.3.jar artifact/
+        run: mvn clean package -Dproject.minecraft.version=1.21.3 -Dproject.nms.version=v1_21_R2 && mv target/tweaks-*+1.21.3.jar artifact/
 
       - name: Build for 1.21.4
-        run: find src \( -type d -name .git -prune \) -o -type f -print0 | xargs -0 sed -i "s/v1_21_R2/v1_21_R3/g" && mvn clean package -Dproject.minecraft.version=1.21.4 && mv target/tweaks-*+1.21.4.jar artifact/
+        run: mvn clean package -Dproject.minecraft.version=1.21.4 -Dproject.nms.version=v1_21_R3 && mv target/tweaks-*+1.21.4.jar artifact/
 
 
 

pom.xml

@@ -16,6 +16,8 @@
         <maven.compiler.source>21</maven.compiler.source>
         <maven.compiler.target>21</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+
+        <project.nms.version>v1_21_R1</project.nms.version>
         <project.minecraft.version>1.21.1</project.minecraft.version>
         <project.spigot.version>${project.minecraft.version}-R0.1-SNAPSHOT</project.spigot.version>
     </properties>
@@ -29,6 +31,31 @@
             </resource>
         </resources>
         <plugins>
+            <plugin>
+                <groupId>com.google.code.maven-replacer-plugin</groupId>
+                <artifactId>replacer</artifactId>
+                <version>1.5.3</version>
+                <executions>
+                    <execution>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>replace</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <includes>
+                        <include>src/**</include>
+                    </includes>
+                    <replacements>
+                        <replacement>
+                            <token>v1_21_R1</token>
+                            <value>${project.nms.version}</value>
+                        </replacement>
+                    </replacements>
+                </configuration>
+            </plugin>
+
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
@@ -59,7 +86,6 @@
                     </execution>
                 </executions>
             </plugin>
-
             <plugin>
                 <groupId>net.md-5</groupId>
                 <artifactId>specialsource-maven-plugin</artifactId>