Automatic setting of BUNDLE_GEMFILE fails on Windows

[blm768]

Ruby version

3.2.2

Code snippet

Gemfile:

source 'https://rubygems.org'

Description

On Windows, if BUNDLE_GEMFILE isn't externally defined, the command that ruby-lsp runs to invoke itself within the bundle will fail. It looks like it's using shell syntax that the default shell on Windows doesn't support.

In a directory with the above Gemfile and a fresh installation of ruby-lsp:

C:\Users\REDACTED\Dev\ruby-test> ruby-lsp
Ruby LSP> Running bundle install for the custom bundle. This may take a while...
'BUNDLE_GEMFILE' is not recognized as an internal or external command,
operable program or batch file.
C:/Users/REDACTED/scoop/persist/ruby/gems/gems/ruby-lsp-0.7.4/exe/ruby-lsp:30:in `exec': No such file or directory - BUNDLE_GEMFILE=.ruby-lsp/Gemfile bundle exec ruby-lsp  (Errno::ENOENT)
        from C:/Users/REDACTED/scoop/persist/ruby/gems/gems/ruby-lsp-0.7.4/exe/ruby-lsp:30:in `<top (required)>'
        from C:/Users/REDACTED/scoop/apps/ruby/current/gems/bin/ruby-lsp:32:in `load'
        from C:/Users/REDACTED/scoop/apps/ruby/current/gems/bin/ruby-lsp:32:in `<main>'

This appears to be related to this VS Code extension issue.

Expected output

ruby-lsp should finish its initialization sequence rather than crashing.