[v3] Cannot package Windows on other platforms, out-of-the-box

[IanVS]

Description

Reference chat: https://discord.com/channels/1042734330029547630/1065600636294549514/1333877905389785188

The templates for create:nsis:installer create a taskfile with backslashes instead of forward slashes, causing the task to fail on non-Windows devices.

To Reproduce

1. Generate a wails 3 project
2. Try to wails3 task windows:package on a non-windows machine
3. It will fail
4. Change the backslashes to forward slashes inside create:nsis:installer in the windows taskfile
5. It will succeed

Expected behaviour

I should be able to build a windows package on non-windows platforms

Screenshots

No response

Attempted Fixes

No response

System Details

Wails (v3.0.0-alpha.9)  Wails Doctor

# System

┌──────────────────────────────────────────────────┐
| Name          | MacOS                            |
| Version       | 15.2                             |
| ID            | 24C101                           |
| Branding      | MacOS 15.2                       |
| Platform      | darwin                           |
| Architecture  | arm64                            |
| Apple Silicon | true                             |
| CPU           | Apple M2 Max                     |
| CPU 1         | Apple M2 Max                     |
| CPU 2         | Apple M2 Max                     |
| GPU           | 30 cores, Metal Support: Metal 3 |
| Memory        | 64 GB                            |
└──────────────────────────────────────────────────┘

# Build Environment

┌────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
| Wails CLI      | v3.0.0-alpha.9                                                                                                            |
| Go Version     | go1.23.5                                                                                                                  |
| -buildmode     | exe                                                                                                                       |
| -compiler      | gc                                                                                                                        |
| CGO_CFLAGS     |                                                                                                                           |
| CGO_CPPFLAGS   |                                                                                                                           |
| CGO_CXXFLAGS   |                                                                                                                           |
| CGO_ENABLED    | 1                                                                                                                         |
| CGO_LDFLAGS    |                                                                                                                           |
| DefaultGODEBUG | asynctimerchan=1,gotypesalias=0,httpservecontentkeepheaders=1,tls3des=1,tlskyber=0,x509keypairleaf=0,x509negativeserial=1 |
| GOARCH         | arm64                                                                                                                     |
| GOARM64        | v8.0                                                                                                                      |
| GOOS           | darwin                                                                                                                    |
└────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

# Dependencies

┌───────────────────────────┐
| Xcode cli tools | 2409    |
| npm             | 10.9.2  |
| *NSIS           | v3.10   |
└─ * - Optional Dependency ─┘

# Diagnosis

 SUCCESS  Your system is ready for Wails development!

Additional context

No response

[leaanthony]

Should be fixed by: #282b420faf878fcb162b131cb9b30267e7fc78f9