fixup! SECURITY.md: document Git for Windows' policies

We no longer update `vs/master` and will probably drop it soon
altogether (besides, it has been the `vs/main` branch for the last
part of its active life).

So let's not describe it in this document any longer.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

SECURITY.md

@@ -36,11 +36,7 @@ Note: even if those builds are not exactly "nightly", they are sometimes referre
 
 ## Following upstream's developments
 
-The [gitforwindows/git repository](https://github.com/git-for-windows/git) also provides the `shears/*` and `vs/master` branches. The `shears/*` branches reflect Git for Windows' patches, rebased onto the upstream integration branches, [updated (mostly) via automated CI builds](https://dev.azure.com/git-for-windows/git/_build?definitionId=25).
-
-# Other special branches
-
-Currently, there is only one other special-purpose branch in Git for Windows: the `vs/master` branch. It adds a commit on top of git-for-Windows/git's `master`, providing the project files ready to build Git in Visual Studio using the MSVC tool chain, [also updated via automated builds](https://dev.azure.com/git-for-windows/git/_build?definitionId=27).
+The [gitforwindows/git repository](https://github.com/git-for-windows/git) also provides the `shears/*` branches. The `shears/*` branches reflect Git for Windows' patches, rebased onto the upstream integration branches, [updated (mostly) via automated CI builds](https://dev.azure.com/git-for-windows/git/_build?definitionId=25).
 
 ## Reporting a Vulnerability