Bump graalvm/setup-graalvm from 1.6.7 to 1.6.8 - #187

Internal server error. Correlation ID: a0f48ed9-39d9-4a40-b3c6-5f00f31cce3e

[CollectorMutability] Avoid `Collectors.to{List,Map,Set}` in favor of collectors that emphasize (im)mutability

[NullAway] returning @nullable expression from method with @nonnull return type

[NullAway] initializer method does not guarantee @nonnull field 'execSignature' (line 50) is initialized along all control-flow paths (remember to check for exceptions or early returns).

[ConstantNaming] Constant variables should adhere to the `UPPER_SNAKE_CASE` naming convention

[NullAway] initializer method does not guarantee @nonnull field 'jarsSignature' (line 63) is initialized along all control-flow paths (remember to check for exceptions or early returns).

[DefaultCharset] Implicit use of the platform default charset, which can result in differing behaviour between JVM executions or incorrect behavior if the encoding of the data source doesn't match expectations.

[DefaultCharset] Implicit use of the platform default charset, which can result in differing behaviour between JVM executions or incorrect behavior if the encoding of the data source doesn't match expectations.

[CollectorMutability] Avoid `Collectors.to{List,Map,Set}` in favor of collectors that emphasize (im)mutability

[NullAway] passing @nullable parameter 'jdkPath.getParent()' where @nonnull is required

[CollectorMutability] Avoid `Collectors.to{List,Map,Set}` in favor of collectors that emphasize (im)mutability