As always, you can get the latest beta version from the "develop" git branch. Alternatively, the self-contained source tarball is at
f38eadda9c (tag: 9.3.rc3, trac/develop) Updated SageMath version to 9.3.rc3
c0dc957ff0 Trac #31479: Do not use pynac's poly_mul_expand function until it has been debugged
749555807d Trac #31592: Upgrade/patch singular more to remove bad -rpath linker options
3e6eaf9dbd Trac #31638: Add mention of Culler's app to install docs for macOS
e531025469 Trac #31515: Updates: sympy 1.7.1, symengine[_py] 0.7
78e8276fa3 Trac #31496: Remove configure message "SAGE_SPKG_CONFIGURE_SAGELIB: command not found"
cb36ec97d0 Trac #27804: spkg-configure.m4, system package info for lrslib
824f9cccaf (tag: 9.3.rc2) Updated SageMath version to 9.3.rc2