build: relocation: Fix long command-line invocations

For applications relocating big parts of the code with many sections,
builds were failing on Windows due to hitting the max command-line
length on that platform.
Fix this by using a file to store the dictionary passed to the python
script.

Fixes https://github.com/zephyrproject-rtos/zephyr/issues/60994

.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>