try removing incremental build files to see if it helps ci disk usage

.drone.yml

@@ -6,6 +6,9 @@ name: test elseware
 concurrency:
     limit: 1
 
+environment:
+  CARGO_INCREMENTAL: false
+
 steps:
 - name: clean cache
   image: rustlang/rust:nightly
@@ -16,8 +19,6 @@ steps:
     path: /drone/src/target
   commands:
   - cargo sweep --maxsize 12GiB
-  environment:
-    CARGO_INCREMENTAL: false
 - name: build
   image: rustlang/rust:nightly
   volumes:
@@ -27,8 +28,6 @@ steps:
     path: /drone/src/target
   commands:
   - cargo build
-  environment:
-    CARGO_INCREMENTAL: false
 - name: clippy!
   image: rustlang/rust:nightly
   volumes:
@@ -38,8 +37,6 @@ steps:
     path: /drone/src/target
   commands:
   - cargo clippy -- --deny warnings
-  environment:
-    CARGO_INCREMENTAL: false
 - name: test
   image: rustlang/rust:nightly
   volumes:
@@ -49,8 +46,6 @@ steps:
     path: /drone/src/target
   commands:
   - cargo test --jobs 1
-  environment:
-    CARGO_INCREMENTAL: false
 
 volumes:
 - name: cache