Make RSpec::Support.thread_local_data thread but not fiber local #600

Job	Run time
Ruby 3.2	57s
Ruby 3.2	1s
Ruby 3.1	59s
Ruby 3.1	1s
Ruby 3.0	1m 5s
Ruby 3.0	1s
Ruby 2.7	1m 46s
Ruby 2.7	1s
Ruby 2.6	1m 27s
Ruby 2.6	1s
Ruby 2.5	1m 25s
Ruby 2.5	1s
Ruby 2.4	1m 20s
Ruby 2.4	1s
Ruby 2.3	1m 38s
Ruby 2.3	1s
Ruby 2.2	1m 58s
Ruby 2.2	1s
Ruby ruby-head	37s
Ruby ruby-head	37s
Ruby jruby-9.2.13.0	2m 57s
Ruby jruby-9.2.13.0	2m 57s
Ruby 2.7 with diff-lcs 1.3	1m 34s
Ruby 2.7 with diff-lcs 1.3	1s
Ruby 2.7 with diff-lcs 1.4.3	1m 29s
Ruby 2.7 with diff-lcs 1.4.3	1s
Rubocop	36s
Rubocop	36s
Legacy Ruby Builds (2.1.9)	41s
Legacy Ruby Builds (2.1.9)	41s
Legacy Ruby Builds (2.0)	39s
Legacy Ruby Builds (2.0)	39s
Legacy Ruby Builds (1.9.3)	43s
Legacy Ruby Builds (1.9.3)	1s
Legacy Ruby Builds (1.9.2)	34s
Legacy Ruby Builds (1.9.2)	1s
Legacy Ruby Builds (1.8.7)	37s
Legacy Ruby Builds (1.8.7)	1s
Legacy Ruby Builds (REE)	38s
Legacy Ruby Builds (REE)	1s
Legacy Ruby Builds (JRuby 1.7)	36s
Legacy Ruby Builds (JRuby 1.7)	1s
Legacy Ruby Builds (JRuby 1.7 1.8 mode)	33s
Legacy Ruby Builds (JRuby 1.7 1.8 mode)	1s
Legacy Ruby Builds (JRuby 9.1.17.0)	1m 13s
Legacy Ruby Builds (JRuby 9.1.17.0)	1m 13s
Ruby 2.7 (Windows)	4m 10s
Ruby 2.7 (Windows)	1s
Ruby 2.6 (Windows)	4m 8s
Ruby 2.6 (Windows)	1s
Ruby 2.5 (Windows)	5m 19s
Ruby 2.5 (Windows)	1s
Ruby 2.4 (Windows)	2m 19s
Ruby 2.4 (Windows)	1s
Ruby 2.3 (Windows)	2m 31s
Ruby 2.3 (Windows)	1s
Ruby 2.2 (Windows)	3m 21s
Ruby 2.2 (Windows)	1s
	54m 56s

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