Add missing self-update feature, fix comments

.github/workflows/build-binaries.yml

@@ -79,7 +79,7 @@ jobs:
         uses: PyO3/maturin-action@v1
         with:
           target: x86_64
-          args: --release --locked --out dist --features production
+          args: --release --locked --out dist --features production,self-update
       - name: "Upload wheels"
         uses: actions/upload-artifact@v4
         with:
@@ -121,7 +121,7 @@ jobs:
         uses: PyO3/maturin-action@v1
         with:
           target: aarch64
-          args: --release --locked --out dist --features production
+          args: --release --locked --out dist --features production,self-update
       - name: "Test wheel - aarch64"
         run: |
           pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
@@ -352,8 +352,7 @@ jobs:
             *.tar.gz
             *.sha256
 
-  # Like `linux-arm`, but use `--no-default-features --features flate2/rust_backend` when
-  # building uv.
+  # Like `linux-arm`, but use `--no-default-features` when building uv.
   linux-s390x:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
     runs-on: ubuntu-latest
@@ -421,8 +420,8 @@ jobs:
             *.tar.gz
             *.sha256
 
-  # Like `linux-arm`, but use `--no-default-features --features flate2/rust_backend` when
-  # building uv, and install the `gcc-powerpc64-linux-gnu` package.
+  # Like `linux-arm`, but use `--no-default-features` when building uv,
+  # and install the `gcc-powerpc64-linux-gnu` package.
   linux-powerpc:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
     runs-on: ubuntu-latest