InexactError on x86

Ran into this on a GitHub Actions instance with Julia 1.3.0 and x86:

```
[1] throw_inexacterror(::Symbol, ::Type{Int32}, ::Int64) at ./boot.jl:560
[2] checked_trunc_sint at ./boot.jl:582 [inlined]
[3] toInt32 at ./boot.jl:619 [inlined]
[4] Int32 at ./boot.jl:709 [inlined]
[5] prune_github_value(::Int64, ::Type{Int32}) at /home/runner/.julia/packages/GitHub/oQdYa/src/utils/GitHubType.jl:74
[6] extract_nullable(::Dict{String,Any}, ::String, ::Type{Int32}) at /home/runner/.julia/packages/GitHub/oQdYa/src/utils/GitHubType.jl:66
[7] macro expansion at /home/runner/.julia/packages/GitHub/oQdYa/src/utils/GitHubType.jl:0 [inlined]
[8] json2github(::Type{GitHub.Status}, ::Dict{String,Any}) at /home/runner/.julia/packages/GitHub/oQdYa/src/utils/GitHubType.jl:93
[9] GitHub.Status(::Dict{String,Any}) at /home/runner/.julia/packages/GitHub/oQdYa/src/repositories/statuses.jl:21
```

```
Julia Version 1.3.0
Commit 46ce4d7933 (2019-11-26 06:09 UTC)
Platform Info:
OS: Linux (i686-pc-linux-gnu)
CPU: Intel(R) Xeon(R) CPU E5-2673 v4 @ 2.30GHz
WORD_SIZE: 32
LIBM: libopenlibm
LLVM: libLLVM-6.0.1 (ORCJIT, broadwell)
```

Start by inspecting src/utils/GitHubType.jl at the reported lines 66–74, then trace how that conversion is reached from src/repositories/statuses.jl. Reproduce the failure on the reported x86 Julia 1.3.0 environment and confirm that status conversion no longer raises InexactError there.

Written by the indexing model from the issue text.