Download wasi-sdk before cleaning the target directory (#63579)

Fix flacks like
https://github.com/zed-industries/zed/actions/runs/33546906778/job/99987145940?pr=63573

`test_extension_store_with_test_extension` gives the extension builder
`target` as its cache at
`crates/extension_host/src/extension_store_test.rs:801`.
`install_dev_extension` performs a real extension and grammar build at
`crates/extension_host/src/extension_host.rs:1139`.
When `target/wasi-sdk` is absent (e.g. after `target/` cleanup), the
builder downloads and extracts it at
`crates/extension/src/extension_builder.rs:511`.

In the failed run, downloading and extracting the SDK consumed 59
seconds, grammar compilation began at 60 seconds, and the timeout fired
immediately.

Release Notes:

- N/A

.github/workflows/release.yml

@@ -40,6 +40,8 @@ jobs:
         tool: nextest
     - name: steps::clear_target_dir_if_large
       run: ./script/clear-target-dir-if-larger-than 350 200
+    - name: steps::download_wasi_sdk
+      run: ./script/download-wasi-sdk
     - name: steps::setup_sccache
       run: ./script/setup-sccache
       env:
@@ -78,8 +80,6 @@ jobs:
         path: ~/.rustup
     - name: steps::setup_linux
       run: ./script/linux
-    - name: steps::download_wasi_sdk
-      run: ./script/download-wasi-sdk
     - name: steps::setup_node
       uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e
       with:
@@ -92,6 +92,8 @@ jobs:
         tool: nextest
     - name: steps::clear_target_dir_if_large
       run: ./script/clear-target-dir-if-larger-than 350 200
+    - name: steps::download_wasi_sdk
+      run: ./script/download-wasi-sdk
     - name: steps::setup_sccache
       run: ./script/setup-sccache
       env:

.github/workflows/release_nightly.yml

@@ -57,8 +57,6 @@ jobs:
         path: ~/.rustup
     - name: steps::setup_linux
       run: ./script/linux
-    - name: steps::download_wasi_sdk
-      run: ./script/download-wasi-sdk
     - name: steps::setup_node
       uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e
       with:
@@ -71,6 +69,8 @@ jobs:
         tool: nextest
     - name: steps::clear_target_dir_if_large
       run: ./script/clear-target-dir-if-larger-than 350 200
+    - name: steps::download_wasi_sdk
+      run: ./script/download-wasi-sdk
     - name: steps::setup_sccache
       run: ./script/setup-sccache
       env:

.github/workflows/run_tests.yml

@@ -394,8 +394,6 @@ jobs:
         path: ~/.rustup
     - name: steps::setup_linux
       run: ./script/linux
-    - name: steps::download_wasi_sdk
-      run: ./script/download-wasi-sdk
     - name: steps::setup_node
       uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e
       with:
@@ -408,6 +406,8 @@ jobs:
         tool: nextest
     - name: steps::clear_target_dir_if_large
       run: ./script/clear-target-dir-if-larger-than 350 200
+    - name: steps::download_wasi_sdk
+      run: ./script/download-wasi-sdk
     - name: steps::setup_sccache
       run: ./script/setup-sccache
       env:
@@ -463,6 +463,8 @@ jobs:
         tool: nextest
     - name: steps::clear_target_dir_if_large
       run: ./script/clear-target-dir-if-larger-than 350 200
+    - name: steps::download_wasi_sdk
+      run: ./script/download-wasi-sdk
     - name: steps::setup_sccache
       run: ./script/setup-sccache
       env: