[buildbot] Switch MLIR buildbot quotes around

The buildbot is a windows buildbot and it is not happy about double quotes in the LLVM cmake arguments. This switches the quotes around.
diff --git a/buildbot/osuosl/master/config/builders.py b/buildbot/osuosl/master/config/builders.py
index 96071ed..e08eaa4 100644
--- a/buildbot/osuosl/master/config/builders.py
+++ b/buildbot/osuosl/master/config/builders.py
@@ -1074,9 +1074,9 @@
                         vs="autodetect",
                         checks=['check-mlir'],
                         extra_configure_args=[
-                            '-DLLVM_BUILD_EXAMPLES=ON',
-                            '-DLLVM_ENABLE_PROJECTS=mlir',
-                            '-DLLVM_TARGETS_TO_BUILD="host;NVPTX;AMDGPU"',
+                            "-DLLVM_BUILD_EXAMPLES=ON",
+                            "-DLLVM_ENABLE_PROJECTS=mlir",
+                            "-DLLVM_TARGETS_TO_BUILD='host;NVPTX;AMDGPU'",
                         ])},
     ]