[Pillow] Removed yum symlinks

[radarhere]

oss-fuzz/projects/pillow/Dockerfile

Lines 32 to 33 in 2ef5c1f

	RUN ln -s /bin/true /usr/local/bin/yum_install \
	&& ln -s /bin/true /usr/local/bin/yum \

These lines can be removed. Pillow no longer needs to suppress errors when calling yum.

They would have been there originally because

• multibuild called yum_install for installing zlib and cmake, but Build zlib on Linux as well python-pillow/pillow-wheels#204 and Do not attempt to install cmake if it is already present python-pillow/Pillow#8593 mean that those are used anymore.
• Pillow called yum to remove zlib-devel, but that is no longer the case after Corrected installing ImageMagick on cifuzz python-pillow/Pillow#8658

cc @hugovk

[github-actions]

radarhere has previously contributed to projects/pillow. The previous PR was #12768