libsForQt5.extra-cmake-modules: fix for strictDeps

[FliegendeWurst]

To fix ECM use in strictDeps builds (#178468), some changes are required.

1. New preConfigure hook to inform CMake about the existence of the package

Since extra-cmake-modules is put in nativeBuildInputs, it is not picked up correctly if strictDeps is true. Pass -DECM_DIR=@out@/share/ECM/cmake to fix it.

2. Bash is added as runtime dependency for some scripts (share/ECM/kde-modules/kde-git-commit-hooks/{clang-format.sh,pre-commit.in})

Things done

• Built on platform(s)
  • x86_64-linux. Cross build is not relevant since ECM always goes in native inputs.
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested compilation of all some packages that depend on this change, just my usual reviews and update work. I have this patched for about two months already.
• Fits CONTRIBUTING.md.

[K900]

Is this specific to the KF5 version of ECM then? Also, the commit hooks should not be used.

[SuperSandro2000]

I am undecided if this is correct or propagatedNativeBuildInputs

[FliegendeWurst]

It is correct by my understanding: extra-cmake-modules in nativeBuildInputs => propagatedBuildInputs are also put in nativeBuildInputs. See #64992

In fact anything you put in propagatedNativeBuildInputs would be ignored.

^ @K900

[K900]

Oh yeah, I forgot this is wrong, lol. Those should probably be saturating, not overflowing... But whatever, out of scope.

[FliegendeWurst]

Is this specific to the KF5 version of ECM then? Also, the commit hooks should not be used.

I think it is. At least the KF6 ECM hasn't caused me trouble yet. About the commit hooks, I just added bash to make sure the output is equivalent to the previous strictDeps = false output. If you want I could remove them from the output instead.

[K900]

I think this is fine, I'm not sure if propagating cmake/pkg-config as buildInputs is correct though.