[Lint] gdalalg_raster_tile.cpp: use std::make_unique<> #28527

Job	Run time
validate_xml_or_json	26s
check-driver-connection-prefix	15s
code_quality_checks	1m 28s
other_checks	45s
cppcheck_2404	31m 4s
binary_files	26s
linting	2m 18s
cppcheck_master	3m 42s
check-config-options	15s
cmake-lint	0s
	40m 39s

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