cargo build via pixi

Author: emilk

.github/workflows/contrib_rerun_py.yml

@@ -61,7 +61,7 @@ jobs:
           # this stops `re_web_viewer_server/build.rs` from running
           RERUN_IS_PUBLISHING: true
         run: |
-          cargo build \
+          pixi run cargo build \
             --locked \
             -p rerun-cli \
             --no-default-features \

.github/workflows/reusable_build_and_upload_rerun_cli.yml

@@ -176,7 +176,7 @@ jobs:
           # this stops `re_web_viewer_server/build.rs` from running
           RERUN_IS_PUBLISHING: true
         run: |
-          cargo build \
+          pixi run cargo build \
             --locked \
             -p rerun-cli \
             --no-default-features \