fix: flaky validations tests

[achettyiitr]

Description

• Too many times, validation tests fail because we are consuming many docker containers, and the docker pool times out and gives EOF error.

https://github.com/rudderlabs/rudder-server/actions/runs/6650806396/job/18071584306?pr=4012
=== Failed
=== FAIL: warehouse/validations TestValidate (63.19s)
    validate_test.go:48: minio: localhost:32899
    validate_test.go:38: 
        	Error Trace:	/home/runner/work/rudder-server/rudder-server/warehouse/validations/validate_test.go:38
        	            				/home/runner/go/pkg/mod/golang.org/x/sync@v0.4.0/errgroup/errgroup.go:75
        	            				/opt/hostedtoolcache/go/1.21.3/x64/src/runtime/asm_amd64.s:1650
        	Error:      	Received unexpected error:
        	            	reached retry deadline: unexpected EOF
        	Test:       	TestValidate
    --- PASS: TestValidate/invalid_path (0.00s)
    --- PASS: TestValidate/steps (0.00s)
    --- PASS: TestValidate/validate (0.00s)

• Sometimes we get a bucket already created error which should not happen since each test is running isolated. It seems like mix-match is happening when too many containers are being created.

https://github.com/rudderlabs/rudder-server/actions/runs/6650207486/job/18069945875
=== Failed
=== FAIL: warehouse/validations TestValidator/Fetch_schema (4.56s)
    validate_test.go:46: 
        	Error Trace:	/home/runner/work/rudder-server/rudder-server/warehouse/validations/validate_test.go:46
        	            				/home/runner/go/pkg/mod/golang.org/x/sync@v0.4.0/errgroup/errgroup.go:75
        	            				/opt/hostedtoolcache/go/1.21.3/x64/src/runtime/asm_amd64.s:1650
        	Error:      	Received unexpected error:
        	            	Your previous request to create the named bucket succeeded and you already own it.
        	Test:       	TestValidator/Fetch_schema
    validate_test.go:40: db: ***localhost:32898/jobsdb?sslmode=disable
    --- FAIL: TestValidator/Fetch_schema (4.56s)

• We can intelligently use single docker for the validation tests since these are isolated with a namespace.

Linear Ticket

• https://linear.app/rudderstack/issue/PIPE-445/validations-tests-fix

Security

• The code changed/added as part of this pull request won't create any security issues with how the software is being used.