PHP8.2 incompatibilities

In PHP8.2, dollar brace string interpolation is deprecated. For the RFC see https://wiki.php.net/rfc/deprecate_dollar_brace_string_interpolation

Thus php-ml is triggering E_DEPRECATED errors.

Unfortunately due to #11 I cannot fix this myself, but quoting the git version of PHPCompatibility scanner:

hans@DESKTOP-EE15SLU:~/projects/PHPCompatibility$ ./vendor/bin/phpcs -p ../php-ml --standard=PHPCompatibility
............................................................  60 / 241 (25%)
..........................................W...W.......W..... 120 / 241 (50%)
............................................................ 180 / 241 (75%)
..........W.....................W..........................W 240 / 241 (100%)
W                                                            241 / 241 (100%)



FILE: /php-ml/src/Classification/DecisionTree.php
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FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
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 389 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${median}
 391 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${median}
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FILE: /php-ml/src/Classification/Linear/DecisionStump.php
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FOUND 0 ERRORS AND 3 WARNINGS AFFECTING 1 LINE
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 90 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${this}
 90 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${this}
 90 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${this}
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FILE: /php-ml/src/Classification/DecisionTree/DecisionTreeLeaf.php
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FOUND 0 ERRORS AND 5 WARNINGS AFFECTING 4 LINES
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 125 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${this}
 135 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${value}
 138 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${col}
 138 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${value}
 141 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${value}
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FILE: /php-ml/src/FeatureExtraction/StopWords.php
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FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
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 28 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${language}
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FILE: /php-ml/src/Helper/OneVsRest.php
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FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
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 160 | WARNING | Using ${var} in strings is deprecated since PHP 8.2, use {$var} instead. Found: ${label}
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FILE: /php-ml/trap/trap.php
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FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
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 5 | WARNING | Using ${v} (variable variables) in strings is deprecated since PHP 8.2, use {${expr}} instead.
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FILE: /php-ml/trap.php
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FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
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 5 | WARNING | Using ${v} (variable variables) in strings is deprecated since PHP 8.2, use {${expr}} instead.
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Edited by hanshenrik