mv instead of rm tools off path for msys2 install

src/ci/scripts/install-msys2.sh

@@ -28,16 +28,19 @@ if isWindows; then
     # Install pacboy for easily installing packages
     pacman -S --noconfirm pactoys
 
-    # Delete these pre-installed tools so we can't accidentally use them, because we are using the
-    # MSYS2 setup action versions instead.
-    # Delete pre-installed version of MSYS2
-    echo "Cleaning up tools in PATH"
-    rm -r "/c/msys64/"
-    # Delete Strawberry Perl, which contains a version of mingw
-    rm -r "/c/Strawberry/"
-    # Delete these other copies of mingw, I don't even know where they come from.
-    rm -r "/c/mingw64/"
-    rm -r "/c/mingw32/"
+    # Remove these pre-installed tools so we can't accidentally use them, because we are using the
+    # MSYS2 setup action versions instead. Because `rm -r`-ing them is slow, we mv them off path
+    # instead.
+    # Remove pre-installed version of MSYS2
+    echo "Cleaning up existing tools in PATH"
+    notpath="/c/NOT/ON/PATH/"
+    mkdir --parents "$notpath"
+    mv -t "$notpath" "/c/msys64/"
+    # Remove Strawberry Perl, which contains a version of mingw
+    mv -t "$notpath" "/c/Strawberry/"
+    # Remove these other copies of mingw, I don't even know where they come from.
+    mv -t "$notpath" "/c/mingw64/"
+    mv -t "$notpath" "/c/mingw32/"
     echo "Finished cleaning up tools in PATH"
 
     if isKnownToBeMingwBuild; then