Add support for imkl 2021.x in numexpr easyblock

[SebastianAchilles]

(created using eb --new-pr)

[SebastianAchilles]

Test report by @SebastianAchilles

Overview of tested easyconfigs (in order)

• SUCCESS SciPy-bundle-2020.11-intel-2020b.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
centos8-eb - Linux centos linux 8.3.2011, x86_64, Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz (skylake), Python 3.6.8
See https://gist.github.com/acc2c65395b79a52d6ab6840641f3f11 for a full test report.

[boegel]

Test report by @boegel

Overview of tested easyconfigs (in order)

• SUCCESS numexpr-2.7.1-foss-2019b-Python-3.7.4.eb
• SUCCESS numexpr-2.7.1-foss-2020a-Python-3.8.2.eb
• SUCCESS numexpr-2.7.1-intel-2019b-Python-2.7.16.eb
• SUCCESS numexpr-2.7.1-intel-2020a-Python-3.8.2.eb

Build succeeded for 4 out of 4 (4 easyconfigs in total)
node3510.doduo.os - Linux RHEL 8.2, x86_64, AMD EPYC 7552 48-Core Processor (zen2), Python 3.6.8
See https://gist.github.com/f58e592bf23d310fa7c053c39adc8047 for a full test report.

[boegel]

lgtm