refactor(upgrade): use Bazel packages to avoid symlinks in the source (#29466)

Previously we had to share code between upgrade/dynamic and upgrade/static
by symlinking the `src` folder, which allowed both packages to access
the upgrade/common files.

These symlinks are always problematic on Windows, where we had to run
a script to re-link them, and restore them.

This change uses Bazel packages to share the `upgrade/common` code,
which avoids the need for symlinking the `src` folder.

Also, the Windows specific scripts that fixup the symlinks have also
been removed as there is no more need for them.

PR Close #29466

scripts/windows/create-symlinks.cmd

@@ -1,2 +0,0 @@
-move /Y packages\upgrade\static\src packages\upgrade\static\src.old
-mklink /D packages\upgrade\static\src ..\src

scripts/windows/create-symlinks.sh

@@ -1,7 +0,0 @@
-#!/usr/bin/env bash
-
-cd `dirname $0`
-
-UPGRADE_STATIC_DIR=./../../packages/upgrade/static
-mv ${UPGRADE_STATIC_DIR}/src ${UPGRADE_STATIC_DIR}/src.old
-cmd <<< "mklink /d \"..\\..\\packages\\upgrade\\static\\src\" \"..\\src\""

scripts/windows/remove-symlinks.sh

@@ -1,7 +0,0 @@
-#!/usr/bin/env bash
-
-cd `dirname $0`
-
-UPGRADE_STATIC_DIR=./../../packages/upgrade/static
-rm ${UPGRADE_STATIC_DIR}/src
-mv ${UPGRADE_STATIC_DIR}/src.old ${UPGRADE_STATIC_DIR}/src