[cipd] Update CIPD client v2.6.7 => v2.6.8.

This adds new optional fields to -json-output:
{
  ...
  "error_code": see cipderr.go for possible values.
  "error_details": {
      "package": "package/path/or/prefix",
      "version": "instance version",
      "subdir": "installation subdir"
  }
}

R=iannucci@chromium.org, ddoman@chromium.org
BUG=1348065

Change-Id: I2a2bf01c180330f83fcf6813150ea1d4faef79c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3824200Reviewed-by: Scott Lee <ddoman@chromium.org>
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>

cipd_client_version

-git_revision:2fe24264d5b4585ecd16ba8e9bb582d8f4b20875
+git_revision:89ada246fcbf10f330011e4991d017332af2365b

cipd_client_version.digests

 # This file was generated by
 #
 #  cipd selfupdate-roll -version-file cipd_client_version \
-#      -version git_revision:2fe24264d5b4585ecd16ba8e9bb582d8f4b20875
+#      -version git_revision:89ada246fcbf10f330011e4991d017332af2365b
 #
 # Do not modify manually. All changes will be overwritten.
 # Use 'cipd selfupdate-roll ...' to modify.
 
-aix-ppc64       sha256  ad77b80d30fe1a92f9a5b09047ba9aeb4394d416a5016fb6b8411f29656339d0
-linux-386       sha256  0a8046bdded1c49fa04627cb37735a088e28e5f5d9f1c82726f00dee9f48c58d
-linux-amd64     sha256  44ac8bdc55f9c2350085670186ab92927e0ef242914639031a4d85152fbaaf12
-linux-arm64     sha256  9a0970dbefd9c5ea69147972af90e293f30a0ed3a7b2792e59b5b3895a3a86ef
-linux-armv6l    sha256  f29bb65efc3d243699392d55c230fe83693c75692407a048a1a8535f1eab76a4
-linux-mips64    sha256  0c773900fb4707425e83106f7ff7b01fcbf871e0d667d9085664e6dfd2b776dd
-linux-mips64le  sha256  09139ee95d53f1f42719d6c1f27d0ff0de2d8bc75589755abdb62c56684ea146
-linux-mipsle    sha256  c5a35423273fd33fe72454e85185f4ceb845cf7a920adacb22150a63e340140b
-linux-ppc64     sha256  86746ffa35f67eb90150f37efac249123bca4948600df42915164ddcb3c62b12
-linux-ppc64le   sha256  ee5564cc68fae33362339fbab415931481c57bd9c3902ede4cc8884d7c98649e
-linux-riscv64   sha256  1b6d2aa7e89e632f27ff458ddd940837d7aa717b34b05350c9aa416e8c9d04b2
-linux-s390x     sha256  2f1ce9af9b7938ad0d22b5b5d909717f4998be9744303f0f48b2c1641db9e252
-mac-amd64       sha256  8fc98441b8e9b3c9b374e4a6bdb122d03c804edce01e24b9880d83b4da796947
-mac-arm64       sha256  568509785cac712e75d7cc5bbe109f19a30d4616fed8c8e86bf50fe5e18694be
-windows-386     sha256  9ebbcb6cd104fcedb6c5a25f7bf0262bbd6fc422cc9a2d7cd5b6171855df06bf
-windows-amd64   sha256  c89a4c027ee7fb79818a077ae3b13a048691fe28bf832bce6fb4d1bfc06907e6
+aix-ppc64       sha256  bf60b679afae76b7d52f46453dc67af6938438c9c8543b40d49f62eb6edb7376
+linux-386       sha256  7f264198598af2ef9d8878349d33c1940f1f3739e46d986962c352ec4cce2690
+linux-amd64     sha256  2ada6b46ad1cd1350522c5c05899d273f5c894c7665e30104e7f57084a5aeeb9
+linux-arm64     sha256  96eca7e49f6732c50122b94b793c3a5e62ed77bce1686787a8334906791b4168
+linux-armv6l    sha256  06394601130652c5e1b055a7e4605c21fc7c6643af0b3b3cac8d2691491afa81
+linux-mips64    sha256  f3eda6542b381b7aa8f582698498b0e197972c894590ec35f18faa467c868f5c
+linux-mips64le  sha256  74229ada8e2afd9c8e7c58991126869b2880547780d4a197a27c1dfa96851622
+linux-mipsle    sha256  2f3c18ec0ad48cd44a9ff39bb60e9afded83ca43fb9c7a5ea9949f6fdd4e1394
+linux-ppc64     sha256  79425c0795fb8ba12b39a8856bf7ccb853e85def4317aa6413222f307d4c2dbd
+linux-ppc64le   sha256  f9b3d85dde70f1b78cd7a41d2477834c15ac713a59317490a4cdac9f8f092325
+linux-riscv64   sha256  bd695164563a66e8d3799e8835f90a398fbae9a4eec24e876c92d5f213943482
+linux-s390x     sha256  6f501af80541e733fda23b4208a21ea05919c95d236036a2121e6b6334a2792c
+mac-amd64       sha256  41d05580c0014912d6c32619c720646fd136e4557c9c7d7571ecc8c0462733a1
+mac-arm64       sha256  dc672bd16d9faf277dd562f1dc00644b10c03c5d838d3cc3d3ea29925d76d931
+windows-386     sha256  fa6ed0022a38ffc51ff8a927e3947fe7e59a64b2019dcddca9d3afacf7630444
+windows-amd64   sha256  b5423e4b4429837f7fe4d571ce99c068aa0ccb37ddbebc1978a423fd2b0086df