restrict shouldAllowIntellisense to only python notebook cells so tha…

[bschnurr]

…t plain .py files dont get duplicate results in api calls to onHover etc.

Fixes # microsoft/pylance-release#3027

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR).
• Title summarizes what is changing.
• Has a news entry file (remember to thank yourself!).
• Appropriate comments and documentation strings in the code.
• Has sufficient logging.
• Has telemetry for feature-requests.
• Unit tests & system/integration tests are added/updated.
• Test plan is updated as appropriate.
• package-lock.json has been regenerated by running npm install (if dependencies have changed).

[codecov-commenter]

Codecov Report

Merging #11106 (79695b2) into main (12a4f20) will decrease coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##            main   #11106   +/-   ##
======================================
- Coverage     63%      63%   -1%     
======================================
  Files        482      482           
  Lines      33839    33891   +52     
  Branches    5517     5529   +12     
======================================
+ Hits       21456    21457    +1     
- Misses     10342    10380   +38     
- Partials    2041     2054   +13     

Impacted Files	Coverage Δ
...andalone/intellisense/intellisenseProvider.node.ts	81% <100%> (+<1%)	⬆️
src/platform/terminals/helper.node.ts	23% <0%> (-56%)	⬇️
src/platform/terminals/shellDetector.node.ts	29% <0%> (-55%)	⬇️
...s/shellDetectors/terminalNameShellDetector.node.ts	35% <0%> (-51%)	⬇️
...terminals/shellDetectors/baseShellDetector.node.ts	70% <0%> (-30%)	⬇️
...latform/common/application/terminalManager.node.ts	33% <0%> (-23%)	⬇️
...inals/shellDetectors/settingsShellDetector.node.ts	24% <0%> (-13%)	⬇️
...shellDetectors/vscEnvironmentShellDetector.node.ts	35% <0%> (-12%)	⬇️
src/notebooks/outputs/tracebackFormatter.ts	93% <0%> (-7%)	⬇️
...hellDetectors/userEnvironmentShellDetector.node.ts	23% <0%> (-7%)	⬇️
... and 265 more

[debonte]

microsoft/pylance-release#3212