Bump codecov-action from v1 to v2 in ci.yml

[fxamacker]

Description

Bump to v2 because codecov-action@v1 is deprecated and can stop working.

See https://github.com/codecov/codecov-action#%EF%B8%8F--deprecration-of-v1

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• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[turbolent]

Thank you!

[github-actions]

Cadence Benchstat comparison

This branch with compared with the base branch onflow:master commit a882c95
The command for i in {1..N}; do go test ./... -run=XXX -bench=. -shuffle=on; done was used.
Bench tests were run a total of 7 times on each branch.

Results

	old.txt	new.txt
	time/op		delta
RuntimeFungibleTokenTransfer-2	1.65ms ±23%	1.45ms ±28%	~	(p=0.165 n=7+7)
RuntimeResourceDictionaryValues-2	18.2ms ± 5%	17.9ms ± 7%	~	(p=0.620 n=7+7)
ParseFungibleToken-2	240µs ± 5%	240µs ± 9%	~	(p=0.945 n=6+7)
ParseDeploy/byte_array-2	32.5ms ± 9%	31.7ms ±22%	~	(p=0.535 n=7+7)
ParseDeploy/decode_hex-2	1.49ms ± 3%	1.46ms ± 3%	~	(p=0.128 n=7+7)
ParseArray-2	19.8ms ± 6%	18.7ms ±15%	~	(p=0.165 n=7+7)
ParseInfix-2	11.0µs ± 4%	10.5µs ±12%	~	(p=0.209 n=7+7)
QualifiedIdentifierCreation/One_level-2	2.90ns ± 5%	2.84ns ± 6%	~	(p=0.301 n=7+7)
QualifiedIdentifierCreation/Three_levels-2	182ns ± 4%	176ns ± 6%	~	(p=0.259 n=7+7)
CheckContractInterfaceFungibleTokenConformance-2	172µs ± 5%	167µs ± 9%	~	(p=0.165 n=7+7)
ContractInterfaceFungibleToken-2	54.0µs ± 9%	51.7µs ±11%	~	(p=0.209 n=7+7)
NewInterpreter/new_interpreter-2	1.52µs ± 8%	1.43µs ± 5%	~	(p=0.053 n=7+7)
NewInterpreter/new_sub-interpreter-2	2.85µs ± 5%	2.84µs ± 9%	~	(p=1.000 n=6+7)
InterpretRecursionFib-2	3.57ms ± 4%	3.44ms ± 4%	−3.61%	(p=0.026 n=7+7)
	alloc/op		delta
RuntimeFungibleTokenTransfer-2	273kB ± 0%	273kB ± 0%	~	(p=0.710 n=7+7)
RuntimeResourceDictionaryValues-2	4.05MB ± 0%	4.05MB ± 0%	~	(p=0.805 n=7+7)
QualifiedIdentifierCreation/One_level-2	0.00B	0.00B	~	(all equal)
QualifiedIdentifierCreation/Three_levels-2	64.0B ± 0%	64.0B ± 0%	~	(all equal)
CheckContractInterfaceFungibleTokenConformance-2	66.2kB ± 0%	66.2kB ± 0%	~	(all equal)
ContractInterfaceFungibleToken-2	26.6kB ± 0%	26.6kB ± 0%	~	(p=1.000 n=7+7)
InterpretRecursionFib-2	1.26MB ± 0%	1.26MB ± 0%	~	(p=0.409 n=7+7)
NewInterpreter/new_interpreter-2	848B ± 0%	848B ± 0%	~	(all equal)
NewInterpreter/new_sub-interpreter-2	1.32kB ± 0%	1.32kB ± 0%	~	(all equal)
	allocs/op		delta
RuntimeFungibleTokenTransfer-2	4.52k ± 0%	4.52k ± 0%	~	(p=0.297 n=7+7)
RuntimeResourceDictionaryValues-2	102k ± 0%	102k ± 0%	~	(p=0.789 n=7+7)
QualifiedIdentifierCreation/One_level-2	0.00	0.00	~	(all equal)
QualifiedIdentifierCreation/Three_levels-2	2.00 ± 0%	2.00 ± 0%	~	(all equal)
CheckContractInterfaceFungibleTokenConformance-2	1.07k ± 0%	1.07k ± 0%	~	(all equal)
ContractInterfaceFungibleToken-2	458 ± 0%	458 ± 0%	~	(all equal)
InterpretRecursionFib-2	26.2k ± 0%	26.2k ± 0%	~	(all equal)
NewInterpreter/new_interpreter-2	13.0 ± 0%	13.0 ± 0%	~	(all equal)
NewInterpreter/new_sub-interpreter-2	39.0 ± 0%	39.0 ± 0%	~	(all equal)