[CI] Update release_tests_binaries Dockerfile to hardcode base image tag

[uditagarwal97]

Before this PR: https://github.com/intel/llvm/actions/runs/18595720667/job/53022842454?pr=20391
After this PR: https://github.com/intel/llvm/actions/runs/18595720667/job/53040472511?pr=20391

This PR fixes the following test failures:

Failed Tests (2):
  SYCL :: Matrix/SG32/joint_matrix_bfloat16.cpp
********************
Unexpectedly Passed Tests (2):
  SYCL :: Matrix/joint_matrix_bfloat16_accumulator.cpp
  SYCL :: Matrix/joint_matrix_half_accumulator.cpp

Hardcoding image tag helps stabilizing igc driver and prevents E2E tests from failing on sycl-rel 6.3 compat testing, when sycl-rel docker image is re-build

[uditagarwal97]

fyi, failure in SeparateCompile/test.cpp is a separate issue - it's because of lit not picking up newly build sycl-post-link and instead using a system installed sycl-post-link binary. I'm working on a PR to fix it as well.