Sync up the vagrant `testJDK.sh` and `testJDKwin.sh` implementations

Since this has run through VPC I'm ok with it and should merge as-is, although we should also create a follow-on issue to sync this up with the non-windows version as far as possible as they seem to have got somewhat out of sync in terms of exactly how they work e.g.

```
mkdir -p $HOME/testLocation
[ ! -d $HOME/testLocation/aqa-tests ] && git clone https://github.com/adoptium/aqa-tests.git $HOME/testLocation/aqa-tests
# cd to aqa-tests as required by https://github.com/adoptium/aqa-tests/issues/2691#issue-932959102
cd $HOME/testLocation/aqa-tests
$HOME/testLocation/aqa-tests/get.sh
cd $HOME/testLocation/aqa-tests/TKG || exit 1
```
vs
```
cd testLocation
if [ ! -d "openjdk-tests" ];
then
echo "Git cloning openjdk-tests"
git clone https://github.com/adoptopenjdk/openjdk-tests
fi
cd openjdk-tests

./get.sh -T $HOME/testLocation/openjdk-tests -p x64_windows
```

_Originally posted by @sxa in https://github.com/adoptium/infrastructure/pull/2790#pullrequestreview-1145405848_

Compare the vagrant testJDK.sh and testJDKwin.sh implementations, starting with the setup and cloning commands shown in the issue. Review the referenced aqa-tests get.sh and TKG paths, then align the two scripts wherever their platform differences allow; done means their test checkout and execution flows are consistently synchronized.

Written by the indexing model from the issue text.