[2.x] Migrate FarmHash usage to xxhash64 (#9267)

Problem
ZAHa, which we use for FarmHash, uses Unsafe.

Solution
This ports xxhash64 to Scala.

.github/workflows/ci.yml

@@ -56,6 +56,10 @@ jobs:
             java: 17
             distribution: zulu
             jobtype: 12
+          # - os: ubuntu-latest
+          #   java: 17
+          #   distribution: temurin
+          #   jobtype: 13
     runs-on: ${{ matrix.os }}
     timeout-minutes: 25
     env:
@@ -202,4 +206,9 @@ jobs:
         if: ${{ matrix.jobtype == 12 }}
         shell: bash
         run: |
-          ./sbt -v "scripted cache/*"
+          ./sbt -v "scripted cache/*"
+      # - name: Hash Benchmark
+      #   if: ${{ matrix.jobtype == 13 }}
+      #   shell: bash
+      #   run: |
+      #     ./sbt -v "hashBenchmark/Jmh/run -i 5 -wi 3 -f1 -t1"