Avoid Win32 MAX_PATH issues by shortening cargo_build_script bin names

[UebelAndre]

I'm running into issues on Windows where cargo_build_script targets are filing to find files. After an investigation, I've found the cause to be paths exceeding the Windows max path length limitation. This change would shorten the runfiles path, potentially keeping some runfiles paths within the 260 character cap

before:

C:\bzl\czfrdgju\execroot\cargo_bazel_examples\bazel-out\x64_windows-opt-exec-2B5CBBC6\bin\external\multi__libnghttp2-sys-0.1.7-1.45.0\libnghttp2-sys_build_script_.exe.runfiles\multi__libnghttp2-sys-0.1.7-1.45.0\nghttp2/lib/includes/nghttp2/nghttp2ver.h.in

after:

C:\bzl\czfrdgju\execroot\cargo_bazel_examples\bazel-out\x64_windows-opt-exec-2B5CBBC6\bin\external\multi__libnghttp2-sys-0.1.7-1.45.0\libnghttp2-sys_build_script_script_.exe.runfiles\multi__libnghttp2-sys-0.1.7-1.45.0\nghttp2/lib/includes/nghttp2/nghttp2ver.h.in

Understandably this doesn't solve for all issues since another target may exceed the character limit again, but every character counts and given that this hasn't been a huge issue, I suspect libnghttp2-sys might just be the extreme case (or we don't have many windows users).

[illicitonion]

Sure :)