profiles: drop BuildIdKind (#584)

Drop `BuildIdKind` in favor of its semantic convention as defined in https://github.com/open-telemetry/semantic-conventions/pull/1329.

Co-authored-by: Tigran Najaryan <4194920+tigrannajaryan@users.noreply.github.com>

opentelemetry/proto/profiles/v1experimental/pprofextended.proto

@@ -271,17 +271,6 @@ message Label {
   int64 num_unit = 4;  // Index into string table
 }
 
-// Indicates the semantics of the build_id field.
-enum BuildIdKind {
-  // Linker-generated build ID, stored in the ELF binary notes.
-  BUILD_ID_LINKER = 0;
-  // Build ID based on the content hash of the binary. Currently no particular
-  // hashing approach is standardized, so a given producer needs to define it
-  // themselves and thus unlike BUILD_ID_LINKER this kind of hash is producer-specific.
-  // We may choose to provide a standardized stable hash recommendation later.
-  BUILD_ID_BINARY_HASH = 1;
-}
-
 // Describes the mapping of a binary in memory, including its address range,
 // file offset, and metadata like build ID
 message Mapping {
@@ -297,12 +286,6 @@ message Mapping {
   // disk for the main binary and shared libraries, or virtual
   // abstractions like "[vdso]".
   int64 filename = 5;  // Index into string table
-  // A string that uniquely identifies a particular program version
-  // with high probability. E.g., for binaries generated by GNU tools,
-  // it could be the contents of the .note.gnu.build-id field.
-  int64 build_id = 6;  // Index into string table
-  // Specifies the kind of build id. See BuildIdKind enum for more details [optional]
-  BuildIdKind build_id_kind = 11;
   // References to attributes in Profile.attribute_table. [optional]
   repeated uint64 attributes = 12;
   // The following fields indicate the resolution of symbolic info.