protobuf: remove gogoproto

Removes gogo/protobuf from buildx and updates to a version of
moby/buildkit where gogo is removed.

This also changes how the proto files are generated. This is because
newer versions of protobuf are more strict about name conflicts. If two
files have the same name (even if they are relative paths) and are used
in different protoc commands, they'll conflict in the registry.

Since protobuf file generation doesn't work very well with
`paths=source_relative`, this removes the `go:generate` expression and
just relies on the dockerfile to perform the generation.

Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>

vendor/golang.org/x/sys/cpu/cpu.go

@@ -105,6 +105,8 @@ var ARM64 struct {
 	HasSVE      bool // Scalable Vector Extensions
 	HasSVE2     bool // Scalable Vector Extensions 2
 	HasASIMDFHM bool // Advanced SIMD multiplication FP16 to FP32
+	HasDIT      bool // Data Independent Timing support
+	HasI8MM     bool // Advanced SIMD Int8 matrix multiplication instructions
 	_           CacheLinePad
 }
 
@@ -199,6 +201,25 @@ var S390X struct {
 	_         CacheLinePad
 }
 
+// RISCV64 contains the supported CPU features and performance characteristics for riscv64
+// platforms. The booleans in RISCV64, with the exception of HasFastMisaligned, indicate
+// the presence of RISC-V extensions.
+//
+// It is safe to assume that all the RV64G extensions are supported and so they are omitted from
+// this structure. As riscv64 Go programs require at least RV64G, the code that populates
+// this structure cannot run successfully if some of the RV64G extensions are missing.
+// The struct is padded to avoid false sharing.
+var RISCV64 struct {
+	_                 CacheLinePad
+	HasFastMisaligned bool // Fast misaligned accesses
+	HasC              bool // Compressed instruction-set extension
+	HasV              bool // Vector extension compatible with RVV 1.0
+	HasZba            bool // Address generation instructions extension
+	HasZbb            bool // Basic bit-manipulation extension
+	HasZbs            bool // Single-bit instructions extension
+	_                 CacheLinePad
+}
+
 func init() {
 	archInit()
 	initOptions()