Libbpf scripting issue

Needs extra Windows Powershell script for Windows builds (has bash scripting)

```
2025-05-20 22:25:08,290 lib.installable.installable INFO Building libbpf 1.2.2 for [vcpp_v19_43_VS17_13_x86,/EHsc /utf-8,Z:\compilers\msvc\14.43.34808-14.43.34810.0\bin\Hostx64,Windows,Debug,x86,,,]
ParserError: C:\tmp\staging\443fcfc6-5d8b-4ec6-93a0-56a9de276451\vcpp_v19_43_VS17_13_x86_1\cebuild.ps1:18
Line |
18 | if [ "$libsfound" = "" ]; then
| ~
| Missing '(' after 'if' in if statement.
```

Start at cebuild.ps1 line 18, where the Windows build fails while parsing bash-style syntax as PowerShell. Compare it with the bash scripting referenced in the issue, then reproduce the libbpf Windows build. Done means the build completes without the PowerShell ParserError.

Written by the indexing model from the issue text.