More CI (#3)

- ci only: use a separate zig cache dir for each run
- use `tools/bazel` everywhere.
- remove arm64 tests. They don't give enough value to be worth the
  brittle environment.
- remove windows execution, except for launcher. Ditto. I will probably
  bring them back.

ci/launcher

@@ -5,8 +5,10 @@
 
 set -xeuo pipefail
 
-ZIG=${ZIG:-$(bazel run "$@" --run_under=echo @zig_sdk//:zig)}
+echo "--- which zig"
+ZIG=${ZIG:-$(tools/bazel run "$@" --run_under=echo @zig_sdk//:zig)}
 
+echo "--- compile launcher.zig for various architectures"
 for target in \
     aarch64-linux-gnu.2.19 \
     aarch64-macos-none \
@@ -17,15 +19,9 @@ do
     $ZIG build-exe -fno-emit-bin -target $target toolchain/launcher.zig
 done
 
+echo "--- zig fmt --check toolchain/launcher.zig"
 $ZIG fmt --check toolchain/launcher.zig
 
+echo "--- zig test toolchain/launcher.zig"
 # until bazel-zig-cc gets a zig toolchain, run launcher's unit tests here.
 $ZIG test toolchain/launcher.zig
-
-# ReleaseSafe because of https://github.com/ziglang/zig/issues/14036
-$ZIG test \
-    -OReleaseSafe \
-    -target x86_64-windows-gnu \
-    --test-cmd wine64-stable \
-    --test-cmd-bin \
-    toolchain/launcher.zig