GitError on Windows with Julia nightly build due to file naming issue of Indexing.jl

When installing this package on Windows with Julia nightly build (with GitHub action julia-buildpkg), I got the following error:

     Cloning [313cdc1a-70c2-5d6a-ae34-0150d3930a38] Indexing from https://github.com/andyferris/Indexing.jl.git
ERROR: GitError(Code:ERROR, Class:Checkout, cannot checkout to invalid path '\')
Stacktrace:
  [1] macro expansion
    @ C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\LibGit2\src\error.jl:110 [inlined]
  [2] checkout_tree(repo::LibGit2.GitRepo, obj::LibGit2.GitTree; options::LibGit2.CheckoutOptions)
    @ LibGit2 C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\LibGit2\src\repository.jl:358
  [3] checkout_tree_to_path(repo::LibGit2.GitRepo, tree::LibGit2.GitTree, path::String)
    @ Pkg.GitTools C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\GitTools.jl:82
  [4] install_git(io::IOContext{Base.PipeEndpoint}, uuid::Base.UUID, name::String, hash::Base.SHA1, urls::Set{String}, version::VersionNumber, version_path::String)
    @ Pkg.Operations C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\Operations.jl:581
  [5] download_source(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}, urls::Dict{Base.UUID, Set{String}}; readonly::Bool)
    @ Pkg.Operations C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\Operations.jl:747
  [6] #download_source#39
    @ C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\Operations.jl:646 [inlined]
  [7] download_source
    @ C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\Operations.jl:644 [inlined]
  [8] up(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}, level::Pkg.Types.UpgradeLevel)
    @ Pkg.Operations C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\Operations.jl:1246
  [9] up(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}; level::Pkg.Types.UpgradeLevel, mode::Pkg.Types.PackageMode, update_registry::Bool, kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Pkg.API C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\API.jl:325
 [10] #up#48
    @ C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\API.jl:147 [inlined]
 [11] instantiate(ctx::Pkg.Types.Context; manifest::Nothing, update_registry::Bool, verbose::Bool, platform::Base.BinaryPlatforms.Platform, allow_autoprecomp::Bool, kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Pkg.API C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\API.jl:1354
 [12] instantiate
    @ C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\API.jl:1336 [inlined]
 [13] build(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}, verbose::Bool)
    @ Pkg.Operations C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\Operations.jl:815
 [14] build(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}; verbose::Bool, kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Pkg.API C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\API.jl:959
 [15] build(pkgs::Vector{Pkg.Types.PackageSpec}; kwargs::Base.Iterators.Pairs{Symbol, Bool, Tuple{Symbol}, NamedTuple{(:verbose,), Tuple{Bool}}})
    @ Pkg.API C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\API.jl:143
 [16] build(; name::Nothing, uuid::Nothing, version::Nothing, url::Nothing, rev::Nothing, path::Nothing, mode::Pkg.Types.PackageMode, subdir::Nothing, kwargs::Base.Iterators.Pairs{Symbol, Bool, Tuple{Symbol}, NamedTuple{(:verbose,), Tuple{Bool}}})
    @ Pkg.API C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.7\Pkg\src\API.jl:159
 [17] top-level scope
    @ none:1
Error: Process completed with exit code 1.

There is a file named \ in the root directory of Indexing.jl. I suspect the above error can be fixed by simply renaming that file.

(I report this issue here rather than under Indexing.jl as I don't see any recent activity there.)

Inspect the root of the Indexing.jl repository for the file named \, then reproduce package installation on Windows with a Julia nightly build using the julia-buildpkg GitHub Action. Verify that the invalid-path error no longer occurs and that the package can be installed successfully.