[upstream_utils] Upgrade to Sleipnir 0.3.2 (#8323)

Also includes a C++ benchmark, which has a Java counterpart in #8236.

upstream_utils/sleipnir_patches/0003-Use-wpi-byteswap.patch

@@ -4,22 +4,11 @@ Date: Tue, 28 Jan 2025 22:19:14 -0800
 Subject: [PATCH 3/8] Use wpi::byteswap()
 
 ---
- include/.styleguide           | 1 +
  include/sleipnir/util/spy.hpp | 3 ++-
- 2 files changed, 3 insertions(+), 1 deletion(-)
+ 1 file changed, 2 insertions(+), 1 deletion(-)
 
-diff --git a/include/.styleguide b/include/.styleguide
-index 4f4c76204071f90bf49eddb8c2aceb583b5e09ba..03938557c2600a7a1f72c6b93c935602f5acb2b2 100644
---- a/include/.styleguide
-+++ b/include/.styleguide
-@@ -10,4 +10,5 @@ includeOtherLibs {
-   ^Eigen/
-   ^fmt/
-   ^gch/
-+  ^wpi/
- }
 diff --git a/include/sleipnir/util/spy.hpp b/include/sleipnir/util/spy.hpp
-index a2f94803e3744cee771669210d1af883160e9896..74dd7990b03783ce805a186920d5142caeb178c6 100644
+index f9143f2b925064e9df5c763823dcf3d435e7aa28..4b810e54a8038162e03cf08fc8eab52b67b2cdd5 100644
 --- a/include/sleipnir/util/spy.hpp
 +++ b/include/sleipnir/util/spy.hpp
 @@ -12,6 +12,7 @@
@@ -28,9 +17,9 @@ index a2f94803e3744cee771669210d1af883160e9896..74dd7990b03783ce805a186920d5142c
  #include <Eigen/SparseCore>
 +#include <wpi/util/bit.hpp>
  
- #include "sleipnir/util/symbol_exports.hpp"
+ namespace slp {
  
-@@ -115,7 +116,7 @@ class SLEIPNIR_DLLEXPORT Spy {
+@@ -114,7 +115,7 @@ class Spy {
     */
    void write32le(int32_t num) {
      if constexpr (std::endian::native != std::endian::little) {