chore(cmake): replace dfu-util with rs-dfu for STM32 flash targets (#7789)

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

tools/setup_buildenv_ubuntu22.04.sh

@@ -84,7 +84,6 @@ sudo apt-get -y install --no-install-recommends \
     clang \
     libclang-dev \
     python-is-python3 \
-    dfu-util \
     nodejs \
     locales \
     stlink-tools \

tools/setup_buildenv_ubuntu24.04.sh

@@ -80,7 +80,6 @@ sudo apt-get -y install --no-install-recommends \
     clang \
     libclang-dev \
     python-is-python3 \
-    dfu-util \
     nodejs \
     locales \
     stlink-tools \