remove ipykernel pin from dev envs

Author: MialLewis

mantid-developer-linux.yml

@@ -15,7 +15,6 @@ dependencies:
   - gsl=2.7 # Keep gsl a specific version to reduce changes in our fitting
   - h5py
   - hdf5>=1.12,<1.13
-  - ipykernel<6 # Added as hard dependency only to deal with an issue with ipykernel v6 and incompatibility with qtconsole/workbench, was previously a soft dependency that was allowed to update to v6 by qtconsole, at present it stops workbench from loading.
   - jemalloc=5.2.0 # We have noticed 5.2.1 can cause a hang on older glibc versions (Cent OS 7, Ubuntu 18.04). Observed with import CaChannel and also our MeierTest.
   - jsoncpp>=1.9.4,<2
   - librdkafka>=1.6.0

mantid-developer-osx.yml

@@ -14,7 +14,6 @@ dependencies:
   - gsl=2.7 # Keep gsl a specific version to reduce changes in our fitting
   - h5py
   - hdf5>=1.12,<1.13
-  - ipykernel<6 # Added as hard dependency only to deal with an issue with ipykernel v6 and incompatibility with qtconsole/workbench, was previously a soft dependency that was allowed to update to v6 by qtconsole, at present it stops workbench from loading.
   - jemalloc>=5.2.1
   - jsoncpp>=1.9.4,<2
   - librdkafka>=1.6.0

mantid-developer-win.yml

@@ -15,7 +15,6 @@ dependencies:
   - gsl=2.7 # Keep gsl a specific version to reduce changes in our fitting
   - h5py
   - hdf5>=1.12,<1.13
-  - ipykernel<6 # Added as hard dependency only to deal with an issue with ipykernel v6 and incompatibility with qtconsole/workbench, was previously a soft dependency that was allowed to update to v6 by qtconsole, at present it stops workbench from loading.
   - jsoncpp>=1.9.4,<2
   - librdkafka>=1.6.0
   - lib3mf # windows only