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.

test/c/BUILD

@@ -13,9 +13,7 @@ cc_binary(
         platform_binary(
             name = "which_libc_{}".format(name),
             src = "which_libc",
-            env = {"QEMU_LD_PREFIX": "/usr/aarch64-linux-gnu"} if "arm64" in name else {},
             platform = platform,
-            run_under = "qemu-aarch64-static" if "arm64" in name else "",
         ),
         sh_test(
             name = "test_libc_{}".format(name),
@@ -31,8 +29,6 @@ cc_binary(
         ("linux_amd64_musl", "//libc_aware/platform:linux_amd64_musl", "non-glibc"),
         ("linux_amd64_gnu.2.19", "//libc_aware/platform:linux_amd64_gnu.2.19", "glibc_2.19"),
         ("linux_amd64_gnu.2.28", "//libc_aware/platform:linux_amd64_gnu.2.28", "glibc_2.28"),
-        ("linux_arm64_musl", "//libc_aware/platform:linux_arm64_musl", "non-glibc"),
         ("linux_amd64", "//platform:linux_amd64", "glibc_2.19"),
-        ("linux_arm64", "//platform:linux_arm64", "glibc_2.28"),
     ]
 ]