ci: set core.autocrlf=false inside MSYS2 shell too

The earlier autocrlf fix ran in a pwsh step, which only configures Git
for Windows. nimble clones its dependency packages from the MSYS2 shell,
whose git reads a separate global config, so autocrlf stayed enabled
there. That kept altering dependency source trees, breaking their SHA1
match against nimble.lock (e.g. the nim package), so nimble re-downloaded
and hung. Repeat the setting in an MSYS2-shell step so nimble's own git
clones produce Linux-identical trees.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.github/workflows/windows-build.yml

@@ -66,6 +66,17 @@ jobs:
           mingw-w64-x86_64-clang
           mingw-w64-x86_64-nasm
 
+    - name: Configure Git in MSYS2 to keep LF line endings
+      # The autocrlf=false above only configures Git for Windows. nimble clones
+      # its dependency packages from within the MSYS2 shell, whose git reads a
+      # separate global config ($HOME/.gitconfig under the MSYS2 root). Without
+      # repeating the setting here, CRLF conversion still alters dependency
+      # source trees, so their SHA1 no longer matches nimble.lock and nimble
+      # re-downloads (and hangs) on every invocation.
+      run: |
+        git config --global core.autocrlf false
+        git config --global core.eol lf
+
     - name: Manually install nasm
       run: |
         bash scripts/install_nasm_in_windows.sh