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/exp/slices/slices.go

@@ -209,25 +209,37 @@ func Insert[S ~[]E, E any](s S, i int, v ...E) S {
 	return s
 }
 
-// Delete removes the elements s[i:j] from s, returning the modified slice.
-// Delete panics if s[i:j] is not a valid slice of s.
-// Delete is O(len(s)-j), so if many items must be deleted, it is better to
-// make a single call deleting them all together than to delete one at a time.
-// Delete might not modify the elements s[len(s)-(j-i):len(s)]. If those
-// elements contain pointers you might consider zeroing those elements so that
-// objects they reference can be garbage collected.
-func Delete[S ~[]E, E any](s S, i, j int) S {
-	_ = s[i:j] // bounds check
+// clearSlice sets all elements up to the length of s to the zero value of E.
+// We may use the builtin clear func instead, and remove clearSlice, when upgrading
+// to Go 1.21+.
+func clearSlice[S ~[]E, E any](s S) {
+	var zero E
+	for i := range s {
+		s[i] = zero
+	}
+}
 
-	return append(s[:i], s[j:]...)
+// Delete removes the elements s[i:j] from s, returning the modified slice.
+// Delete panics if j > len(s) or s[i:j] is not a valid slice of s.
+// Delete is O(len(s)-i), so if many items must be deleted, it is better to
+// make a single call deleting them all together than to delete one at a time.
+// Delete zeroes the elements s[len(s)-(j-i):len(s)].
+func Delete[S ~[]E, E any](s S, i, j int) S {
+	_ = s[i:j:len(s)] // bounds check
+
+	if i == j {
+		return s
+	}
+
+	oldlen := len(s)
+	s = append(s[:i], s[j:]...)
+	clearSlice(s[len(s):oldlen]) // zero/nil out the obsolete elements, for GC
+	return s
 }
 
 // DeleteFunc removes any elements from s for which del returns true,
 // returning the modified slice.
-// When DeleteFunc removes m elements, it might not modify the elements
-// s[len(s)-m:len(s)]. If those elements contain pointers you might consider
-// zeroing those elements so that objects they reference can be garbage
-// collected.
+// DeleteFunc zeroes the elements between the new length and the original length.
 func DeleteFunc[S ~[]E, E any](s S, del func(E) bool) S {
 	i := IndexFunc(s, del)
 	if i == -1 {
@@ -240,11 +252,13 @@ func DeleteFunc[S ~[]E, E any](s S, del func(E) bool) S {
 			i++
 		}
 	}
+	clearSlice(s[i:]) // zero/nil out the obsolete elements, for GC
 	return s[:i]
 }
 
 // Replace replaces the elements s[i:j] by the given v, and returns the
 // modified slice. Replace panics if s[i:j] is not a valid slice of s.
+// When len(v) < (j-i), Replace zeroes the elements between the new length and the original length.
 func Replace[S ~[]E, E any](s S, i, j int, v ...E) S {
 	_ = s[i:j] // verify that i:j is a valid subslice
 
@@ -272,6 +286,7 @@ func Replace[S ~[]E, E any](s S, i, j int, v ...E) S {
 		if i+len(v) != j {
 			copy(r[i+len(v):], s[j:])
 		}
+		clearSlice(s[tot:]) // zero/nil out the obsolete elements, for GC
 		return r
 	}
 
@@ -345,9 +360,7 @@ func Clone[S ~[]E, E any](s S) S {
 // This is like the uniq command found on Unix.
 // Compact modifies the contents of the slice s and returns the modified slice,
 // which may have a smaller length.
-// When Compact discards m elements in total, it might not modify the elements
-// s[len(s)-m:len(s)]. If those elements contain pointers you might consider
-// zeroing those elements so that objects they reference can be garbage collected.
+// Compact zeroes the elements between the new length and the original length.
 func Compact[S ~[]E, E comparable](s S) S {
 	if len(s) < 2 {
 		return s
@@ -361,11 +374,13 @@ func Compact[S ~[]E, E comparable](s S) S {
 			i++
 		}
 	}
+	clearSlice(s[i:]) // zero/nil out the obsolete elements, for GC
 	return s[:i]
 }
 
 // CompactFunc is like [Compact] but uses an equality function to compare elements.
 // For runs of elements that compare equal, CompactFunc keeps the first one.
+// CompactFunc zeroes the elements between the new length and the original length.
 func CompactFunc[S ~[]E, E any](s S, eq func(E, E) bool) S {
 	if len(s) < 2 {
 		return s
@@ -379,6 +394,7 @@ func CompactFunc[S ~[]E, E any](s S, eq func(E, E) bool) S {
 			i++
 		}
 	}
+	clearSlice(s[i:]) // zero/nil out the obsolete elements, for GC
 	return s[:i]
 }