update QScintilla easyblock to be compatible with PyQt5 >= 5.15

[akesandgren]

(created using eb --new-pr)

[akesandgren]

Test report by @akesandgren

Overview of tested easyconfigs (in order)

• SUCCESS QScintilla-2.11.6-GCCcore-11.2.0.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
b-an02.hpc2n.umu.se - Linux Ubuntu 20.04, x86_64, Intel(R) Xeon(R) CPU E5-2690 v4 @ 2.60GHz, Python 3.8.10
See https://gist.github.com/c67cc6900cf1ce9fc420ee5d7795e4c1 for a full test report.

[jfgrimm]

Test report by @jfgrimm

Overview of tested easyconfigs (in order)

• SUCCESS QScintilla-2.11.6-GCCcore-11.2.0.eb
• SUCCESS re2c-1.1.1-GCCcore-8.2.0.eb
• SUCCESS double-conversion-3.1.4-GCCcore-8.2.0.eb
• SUCCESS PCRE2-10.33-GCCcore-8.2.0.eb
• SUCCESS DBus-1.13.8-GCCcore-8.2.0.eb
• SUCCESS libevent-2.1.8-GCCcore-8.2.0.eb
• SUCCESS Qt5-5.12.3-GCCcore-8.2.0.eb
• FAIL (build issue) PyQt5-5.12.1-GCCcore-8.2.0-Python-3.7.2.eb (partial log available at https://gist.github.com/bfbc37e8a77563331ffc2da53f7eeaa0)
• FAIL (build issue) QScintilla-2.11.2-GCCcore-8.2.0-Python-3.7.2.eb (partial log available at https://gist.github.com/4c714e87bdfef00e2ace66088ddeca96)

Build succeeded for 7 out of 9 (2 easyconfigs in total)
himem03.pri.viking.alces.network - Linux CentOS Linux 7.9.2009, x86_64, Intel(R) Xeon(R) Gold 6130 CPU @ 2.10GHz (skylake_avx512), Python 3.6.8
See https://gist.github.com/a478edf627414f7cdac8ea9d2a55491b for a full test

nb PyQt5 w/ GCCcore 8.2.0 failed due to sip source no longer being available

[jfgrimm]

lgtm

[jfgrimm]

Going in, thanks @akesandgren!