Modified the external-mesa branch to point to main

Tracked-On: OAM-122061
Signed-off-by: tprabhu <[email protected]>

include/bsp-celadon.xml

@@ -85,9 +85,7 @@
     <annotation name="readonly" value="true"/>
   </project>
   <project name="external-libdrm" path="hardware/intel/external/drm-intel" remote="github" revision="v2.4.115" />
-  <project name="external-mesa" path="hardware/intel/external/mesa3d-intel" remote="github" revision="celadon/s/mr0/master">
-    <annotation name="readonly" value="true"/>
-  </project>
+  <project name="external-mesa" path="hardware/intel/external/mesa3d-intel" remote="github" revision="main" />
   <project name="minigbm" path="hardware/intel/external/minigbm-intel"  remote="github" revision="upstream_main" />
   <project name="pub/scm/linux/kernel/git/firmware/linux-firmware" path="vendor/linux/firmware" remote="kernel.googlesource" revision="refs/tags/20240220"/>
   <project name="kernel-modules" path="kernel/modules" remote="github" revision="master"/>