Only set safe.directory on Cygwin (which needs it)

This stops setting the current directory as an explicit safe
directory on CI for non-Windows systems, where this is not needed
because the repository has the ownership Git expects. The step name
is updated accordingly to reflect its now narrower purpose.

This also adds shell quoting to $(pwd) in the Cygwin workflow. In
practice, on CI, the path is very unlikely to contain whitespace,
but double-quoting $ expansions on which splitting and globbing are
unwanted is more robust and better expresses intent. This also has
the benefit that users who use the CI workflows as a guide to
commands they run locally, where on Windows they may very well have
spaces somewhere in this absolute path, will use a correct command.

.github/workflows/cygwin-test.yml

@@ -12,7 +12,7 @@ jobs:
       SHELLOPTS: igncr
       TMP: "/tmp"
       TEMP: "/tmp"
-    
+
     steps:
     - name: Force LF line endings
       run: git config --global core.autocrlf input
@@ -24,8 +24,8 @@ jobs:
         packages: python39 python39-pip python39-virtualenv git
     - name: Tell git to trust this repo
       shell: bash.exe -eo pipefail -o igncr "{0}"
-      run: | 
-          /usr/bin/git config --global --add safe.directory $(pwd)
+      run: |
+          /usr/bin/git config --global --add safe.directory "$(pwd)"
           /usr/bin/git config --global protocol.file.allow always
     - name: Install dependencies and prepare tests
       shell: bash.exe -eo pipefail -o igncr "{0}"

.github/workflows/pythonpackage.yml

@@ -52,9 +52,8 @@ jobs:
         set -x
         mypy -p git
 
-    - name: Tell git to trust this repo
-      run: | 
-          /usr/bin/git config --global --add safe.directory $(pwd)
+    - name: Tell git to allow file protocol even for submodules
+      run: |
           /usr/bin/git config --global protocol.file.allow always
 
     - name: Test with pytest