ARROW-12444: [Rust] Remove rust

Removes rust from this repository and uses git clone to fetch the arrow-rs repo for integration tests.

Each commit is an independent change.

Note: Rust implementations have moved to:
* https://github.com/apache/arrow-rs
* https://github.com/apache/arrow-datafusion

Closes #10096 from jorgecarleitao/rm-rust

Authored-by: Jorge C. Leitao <jorgecarleitao@gmail.com>
Signed-off-by: Krisztián Szűcs <szucs.krisztian@gmail.com>

.env

@@ -47,7 +47,6 @@ FEDORA=33
 PYTHON=3.6
 LLVM=12
 CLANG_TOOLS=8
-RUST=nightly-2021-03-24
 GO=1.15
 NODE=14
 MAVEN=3.5.4

.github/workflows/cancel.yml

@@ -115,10 +115,3 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
           workflowFileName: ruby.yml
           skipEventTypes: '["push", "schedule"]'
-      - uses: potiuk/cancel-workflow-runs@master
-        name: "Cancel stale Rust runs"
-        with:
-          cancelMode: allDuplicates
-          token: ${{ secrets.GITHUB_TOKEN }}
-          workflowFileName: rust.yml
-          skipEventTypes: '["push", "schedule"]'

.github/workflows/dev.yml

@@ -29,7 +29,7 @@ env:
 jobs:
 
   lint:
-    name: Lint C++, Python, R, Rust, Docker, RAT
+    name: Lint C++, Python, R, Docker, RAT
     runs-on: ubuntu-latest
     if: ${{ !contains(github.event.pull_request.title, 'WIP') }}
     steps:

.github/workflows/dev_pr/labeler.yml

@@ -45,19 +45,9 @@ lang-R:
 lang-ruby:
   - ruby/**/*
 
-lang-rust:
-  - rust/**/*
-
-datafusion:
-  - rust/datafusion/**/*
-
-ballista:
-  - rust/ballista/**/*
-
 flight:
   - cpp/src/arrow/flight/**/*
   - r/R/flight.*
-  - rust/arrow-flight/**/*
   - python/pyarrow/*flight.*
 
 gandiva:
@@ -71,4 +61,3 @@ parquet:
   - cpp/src/parquet/**/*
   - r/R/parquet.*
   - ruby/red-parquet/**/*
-  - rust/parquet*/**/*

.github/workflows/integration.yml

@@ -62,6 +62,11 @@ jobs:
           fetch-depth: 0
       - name: Fetch Submodules and Tags
         run: ci/scripts/util_checkout.sh
+      - name: Checkout Arrow Rust
+        uses: actions/checkout@v2
+        with:
+          repository: apache/arrow-rs
+          path: rust
       - name: Free Up Disk Space
         run: ci/scripts/util_cleanup.sh
       - name: Cache Docker Volumes