meta: Delete bogus assertion

_mesa_meta_begin forces the API to API_OPENGL_COMPAT, so the assertion
can never trigger.
22 jobs for !856 with review/meta-clean-ups in 35 minutes and 5 seconds (queued for 39 seconds)
latest detached
Status Job ID Name Coverage
  Containers Build
passed #541162
debian

00:00:26

 
  Build+Test
passed #541171
meson-arm64

00:01:34

passed #541170
meson-armhf

00:02:23

passed #541164
meson-clang

00:09:28

passed #541168
meson-clover

00:09:21

passed #541172
meson-i386

00:02:25

passed #541167
meson-main

00:07:37

passed #541163
meson-swr-glvnd

00:06:30

passed #541169
meson-vulkan

00:02:06

passed #541174
scons-llvm

00:02:31

passed #541173
scons-nollvm

00:03:40

passed #541165
scons-swr

00:07:32

passed #541166
scons-win64

00:09:28

 
  Test
passed #541175
test-llvmpipe-gles2 1/4

00:03:45

passed #541176
test-llvmpipe-gles2 2/4

00:04:08

passed #541177
test-llvmpipe-gles2 3/4

00:05:30

passed #541178
test-llvmpipe-gles2 4/4

00:02:32

passed #541179
test-softpipe-gles2 1/4

00:01:28

passed #541180
test-softpipe-gles2 2/4

00:01:40

passed #541181
test-softpipe-gles2 3/4

00:01:01

passed #541182
test-softpipe-gles2 4/4

00:01:42

passed #541183
test-softpipe-gles3-limited

00:02:25