Fix single instance lock reset on macOS

[APshenkin]

Description

Flock file lock is reset, because lock file is GC by go. This PR change it so that this file is keeping during application live

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Tested with demo app

• Windows
• macOS
• Linux

Test Configuration

# Wails
Version  | v2.8.1
Revision | 9a069653e2a67b94cbdf121066c8a580894914c0
Modified | true

# System
┌────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
| OS           | MacOS                                                                                                                       |
| Version      | 14.5                                                                                                                        |
| ID           | 23F79                                                                                                                       |
| Go Version   | go1.22.1                                                                                                                    |
| Platform     | darwin                                                                                                                      |
| Architecture | arm64                                                                                                                       |
| CPU          | Apple M1 Max                                                                                                                |
| GPU          | Chipset Model: Apple M1 Max Type: GPU Bus: Built-In Total Number of Cores: 32 Vendor: Apple (0x106b) Metal Support: Metal 3 |
| Memory       | 32GB                                                                                                                        |
└────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

# Dependencies
┌──────────────────────────────────────────────────────────────────────┐
| Dependency                | Package Name | Status    | Version       |
| Xcode command line tools  | N/A          | Installed | 2408          |
| Nodejs                    | N/A          | Installed | 20.10.0       |
| npm                       | N/A          | Installed | 10.2.3        |
| *Xcode                    | N/A          | Installed | 15.4 (15F31d) |
| *upx                      | N/A          | Available |               |
| *nsis                     | N/A          | Installed | v3.09         |
└────────────────────── * - Optional Dependency ───────────────────────┘

Checklist:

• I have updated website/src/pages/changelog.mdx with details of this PR
• My code follows the general coding style of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[leaanthony]

Thanks so much for circling back on this 🙏