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"),
     ]
 ]

test/cgo/BUILD

@@ -44,14 +44,10 @@ go_binary(
     platform_test(
         name = "cgo_test_{}".format(name),
         src = "cgo_test",
-        env = {"QEMU_LD_PREFIX": "/usr/aarch64-linux-gnu"} if is_arm64 else {},
         platform = platform,
-        run_under = "qemu-aarch64-static" if is_arm64 else "",
     )
     for name, platform, is_arm64 in [
         ("linux_amd64_musl", "//libc_aware/platform:linux_amd64_musl", False),
         ("linux_amd64_gnu.2.19", "//libc_aware/platform:linux_amd64_gnu.2.19", False),
-        ("linux_arm64_musl", "//libc_aware/platform:linux_arm64_musl", True),
-        ("linux_arm64_gnu.2.28", "//libc_aware/platform:linux_arm64_gnu.2.28", True),
     ]
 ]

test/windows/BUILD

@@ -9,12 +9,19 @@ cc_binary(
     tags = ["manual"],
 )
 
-platform_test(
+# TODO(motiejus): bring back windows tests, not only builds
+#platform_test(
+#    name = "winver_windows_amd64",
+#    src = "winver",
+#    platform = "//platform:windows_amd64",
+#    run_under = "wine64-stable",
+#    tags = ["no-sandbox"],
+#)
+
+platform_binary(
     name = "winver_windows_amd64",
     src = "winver",
     platform = "//platform:windows_amd64",
-    run_under = "wine64-stable",
-    tags = ["no-sandbox"],
 )
 
 platform_binary(