[SPARK-35709][DOCS] Remove the reference to third party Nomad integration project
[SPARK-35709][DOCS] Remove the reference to third party Nomad integration project

### What changes were proposed in this pull request?
This PR updates documentation by removing reference to [hashicorp/nomad-spark](https://github.com/hashicorp/nomad-spark) which has been deprecated in April 2020, and will not be developed any longer.

### Why are the changes needed?
To keep the documentation updated and remove confusion for potential users being interested in running with Nomad.

### Does this PR introduce _any_ user-facing change?
Yes. A change to the documentation.

### How was this patch tested?
Generated to documentation, and checked everything is alright in the output.

Closes #32860 from pptaszynski/doc/remove-spark-nomad-project-reference.

Authored-by: Pawel Ptaszynski <8026d7a04d9473dcc4b202389e9f3c3ae4b218fa@bolt.eu>
Signed-off-by: Takeshi Yamamuro <9770f4f4b25a32d3dfa34670a10767defeb974f3@apache.org>

wangyum/spark,nchammas/spark,vinodkc/spark,shaneknapp/spark,hvanhovell/spark,vinodkc/spark,gengliangwang/spark,nchammas/spark,ueshin/apache-spark,ueshin/apache-spark,taroplus/spark,rednaxelafx/apache-spark,holdenk/spark,chuckchen/spark,srowen/spark,HyukjinKwon/spark,HyukjinKwon/spark,apache/spark,milliman/spark,mahak/spark,HyukjinKwon/spark,gengliangwang/spark,taroplus/spark,HyukjinKwon/spark,apache/spark,wangmiao1981/spark,zzcclp/spark,JoshRosen/spark,maropu/spark,zero323/spark,xuanyuanking/spark,holdenk/spark,srowen/spark,wangmiao1981/spark,xuanyuanking/spark,rednaxelafx/apache-spark,hvanhovell/spark,WeichenXu123/spark,milliman/spark,maropu/spark,apache/spark,zero323/spark,holdenk/spark,dongjoon-hyun/spark,vinodkc/spark,witgo/spark,wangmiao1981/spark,witgo/spark,shaneknapp/spark,gengliangwang/spark,wangyum/spark,shaneknapp/spark,nchammas/spark,wangyum/spark,zzcclp/spark,taroplus/spark,gengliangwang/spark,wangyum/spark,milliman/spark,srowen/spark,mahak/spark,hvanhovell/spark,taroplus/spark,JoshRosen/spark,gengliangwang/spark,milliman/spark,wangyum/spark,wangyum/spark,mahak/spark,WeichenXu123/spark,zzcclp/spark,srowen/spark,rednaxelafx/apache-spark,WeichenXu123/spark,hvanhovell/spark,xuanyuanking/spark,ueshin/apache-spark,vinodkc/spark,dongjoon-hyun/spark,JoshRosen/spark,shaneknapp/spark,mahak/spark,wangyum/spark,jiangxb1987/spark,dongjoon-hyun/spark,milliman/spark,taroplus/spark,holdenk/spark,JoshRosen/spark,jiangxb1987/spark,shaneknapp/spark,gengliangwang/spark,JoshRosen/spark,zero323/spark,zzcclp/spark,chuckchen/spark,jiangxb1987/spark,apache/spark,shaneknapp/spark,cloud-fan/spark,taroplus/spark,jiangxb1987/spark,srowen/spark,chuckchen/spark,WeichenXu123/spark,rednaxelafx/apache-spark,nchammas/spark,cloud-fan/spark,cloud-fan/spark,chuckchen/spark,jiangxb1987/spark,nchammas/spark,vinodkc/spark,xuanyuanking/spark,cloud-fan/spark,wangmiao1981/spark,rednaxelafx/apache-spark,taroplus/spark,maropu/spark,zero323/spark,mahak/spark,witgo/spark,milliman/spark,chuckchen/spark,xuanyuanking/spark,dongjoon-hyun/spark,maropu/spark,ueshin/apache-spark,maropu/spark,maropu/spark,WeichenXu123/spark,srowen/spark,rednaxelafx/apache-spark,rednaxelafx/apache-spark,vinodkc/spark,cloud-fan/spark,chuckchen/spark,zero323/spark,dongjoon-hyun/spark,mahak/spark,hvanhovell/spark,WeichenXu123/spark,srowen/spark,holdenk/spark,zero323/spark,holdenk/spark,ueshin/apache-spark,HyukjinKwon/spark,WeichenXu123/spark,zzcclp/spark,witgo/spark,holdenk/spark,cloud-fan/spark,xuanyuanking/spark,wangmiao1981/spark,witgo/spark,nchammas/spark,ueshin/apache-spark,dongjoon-hyun/spark,hvanhovell/spark,wangmiao1981/spark,hvanhovell/spark,vinodkc/spark,shaneknapp/spark,HyukjinKwon/spark,zzcclp/spark,apache/spark,dongjoon-hyun/spark,HyukjinKwon/spark,zzcclp/spark,mahak/spark,gengliangwang/spark,jiangxb1987/spark,apache/spark,nchammas/spark,maropu/spark,zero323/spark,cloud-fan/spark,xuanyuanking/spark,chuckchen/spark,witgo/spark,wangmiao1981/spark,ueshin/apache-spark,apache/spark,JoshRosen/spark,JoshRosen/spark,milliman/spark,jiangxb1987/spark,witgo/spark