Revert "Make BitArray.{slice_bits,slice_shots,__getitem__} raise IndexError when indices are not valid (backport #12755)"

[mtreinish]

This commit reverts #12844, the original PR was making an API change as a bugfix (to make the api consistent with other similar APIs). However it is still a change in the defined stable interface of the class as documented and we shouldn't be changing that per the stability guidelines of the project. Especially in a patch version bugfix release. We can debate whether the change is acceptable for 1.2.0 independently but for a patch version it is definitely out of scope.

[qiskit-bot]

One or more of the following people are relevant to this code:

• @Qiskit/terra-core
• @ajavadia
• @levbishop
• @t-imamichi

[coveralls]

Pull Request Test Coverage Report for Build 10308586130

Details

• 3 of 4 (75.0%) changed or added relevant lines in 1 file are covered.
• 18 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.01%) to 89.938%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit/primitives/containers/bit_array.py	3	4	75.0%

Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/lex.rs	6	92.23%
crates/qasm2/src/parse.rs	12	97.15%

Totals
Change from base Build 10296040200:	-0.01%
Covered Lines:	61847
Relevant Lines:	68766

---

💛 - Coveralls