Update .gitignore to include /buildSrc/ subdirectories

Add /buildSrc/.gradle to .gitignore
Add /buildSrc/build/ to .gitignore
Remove outdated /run directories

[no changelog]

.gitignore

@@ -2,8 +2,10 @@
 #
 # SPDX-License-Identifier: CC0-1.0
 
-.gradle
+/.gradle
 /build/
+/buildSrc/.gradle
+/buildSrc/build/
 
 # Ignore Gradle GUI config
 gradle-app.setting
@@ -20,12 +22,5 @@ gradle-app.setting
 # IDEA
 /.idea/
 
-# Architectury-loom runClient
-/common/build/
-/forge/build/
-/fabric/build/
-/quilt/build/
-/forge/run/
-/fabric/run/
-/quilt/run/
+# loom runClient
 /run/