Renumber SPIRVUnifiedDescriptorHeapStride 153 -> 154

At merge time this PR collided with the concurrently-queued #11556, which
appends CompilerVersion = 153 to CompilerOptionName. Both PRs branched when
the enum tail was TraceCoverageBoolean = 152 and each took the next free value
153, producing a `duplicate case value` build break in the OptionKind switch
(slang-options.cpp) once combined in a merge group.

Yield 153 to #11556's CompilerVersion and append this option at 154 instead.
Append-only, so no existing enumerator value shifts (ABI-safe). The two now
hold distinct values regardless of merge order.

Author: nv-slang-bot[bot]

include/slang.h

@@ -1204,7 +1204,7 @@ typedef uint32_t SlangSizeT;
                  //   watchdog timeouts heavy coverage can trigger) at the cost of exact
                  //   counts. Off by default.
         SPIRVUnifiedDescriptorHeapStride =
-            153, // bool: when set, emit each SPIRV resource descriptor-heap runtime array's
+            154, // bool: when set, emit each SPIRV resource descriptor-heap runtime array's
                  //   ArrayStride as the maximum of image and buffer descriptor sizes, so a
                  //   single heap shared by buffers and images is indexed at the device's unified
                  //   stride. Opt-in; mutually exclusive with a non-zero