fix(core): Avoid error messages when deleting non-existent environment variable

[HUMORCE]

Description

Motivation and Context

Issue:
When delete environment variable during uninstallation, if the environment variable has been deleted before, we will get a error message.
Examples:

1. Same environment variable (name) provide by multiple manifests
2. Delete manually

How Has This Been Tested?

Before:

PS C:\Users\WDAGUtilityAccount> scoop install openssl1 openssl1-light
Installing 'openssl1' (1.1.1u) [64bit] from versions bucket
Loading Win64OpenSSL-1_1_1u.exe from cache
Checking hash of Win64OpenSSL-1_1_1u.exe ... ok.
Extracting Win64OpenSSL-1_1_1u.exe ... done.
Linking ~\scoop\apps\openssl1\current => ~\scoop\apps\openssl1\1.1.1u
Creating shim for 'openssl'.
'openssl1' (1.1.1u) was installed successfully!
Installing 'openssl1-light' (1.1.1u) [64bit] from versions bucket
Loading Win64OpenSSL_Light-1_1_1u.exe from cache
Checking hash of Win64OpenSSL_Light-1_1_1u.exe ... ok.
Extracting Win64OpenSSL_Light-1_1_1u.exe ... done.
Linking ~\scoop\apps\openssl1-light\current => ~\scoop\apps\openssl1-light\1.1.1u
Creating shim for 'openssl'.
WARN  Overwriting shim ('openssl.exe' -> 'openssl.exe') installed from openssl1
'openssl1-light' (1.1.1u) was installed successfully!
PS C:\Users\WDAGUtilityAccount> scoop uninstall openssl1 openssl1-light
Uninstalling 'openssl1' (1.1.1u).
Removing shim 'openssl.shim.openssl1'.
Unlinking ~\scoop\apps\openssl1\current
'openssl1' was uninstalled.
Uninstalling 'openssl1-light' (1.1.1u).
Removing shim 'openssl.shim'.
Removing shim 'openssl.exe'.
Unlinking ~\scoop\apps\openssl1-light\current
Exception calling "DeleteValue" with "1" argument(s): "No value exists with that name."
At C:\Users\WDAGUtilityAccount\scoop\apps\scoop\current\lib\core.ps1:701 char:9
+         $EnvRegisterKey.DeleteValue($name)
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : ArgumentException

'openssl1-light' was uninstalled.

After:

PS C:\Users\WDAGUtilityAccount> scoop install openssl1 openssl1-light
Installing 'openssl1' (1.1.1u) [64bit] from versions bucket
Loading Win64OpenSSL-1_1_1u.exe from cache
Checking hash of Win64OpenSSL-1_1_1u.exe ... ok.
Extracting Win64OpenSSL-1_1_1u.exe ... done.
Linking ~\scoop\apps\openssl1\current => ~\scoop\apps\openssl1\1.1.1u
Creating shim for 'openssl'.
'openssl1' (1.1.1u) was installed successfully!
Installing 'openssl1-light' (1.1.1u) [64bit] from versions bucket
Loading Win64OpenSSL_Light-1_1_1u.exe from cache
Checking hash of Win64OpenSSL_Light-1_1_1u.exe ... ok.
Extracting Win64OpenSSL_Light-1_1_1u.exe ... done.
Linking ~\scoop\apps\openssl1-light\current => ~\scoop\apps\openssl1-light\1.1.1u
Creating shim for 'openssl'.
WARN  Overwriting shim ('openssl.exe' -> 'openssl.exe') installed from openssl1
'openssl1-light' (1.1.1u) was installed successfully!
PS C:\Users\WDAGUtilityAccount> scoop uninstall openssl1 openssl1-light
Uninstalling 'openssl1' (1.1.1u).
Removing shim 'openssl.shim.openssl1'.
Unlinking ~\scoop\apps\openssl1\current
'openssl1' was uninstalled.
Uninstalling 'openssl1-light' (1.1.1u).
Removing shim 'openssl.shim'.
Removing shim 'openssl.exe'.
Unlinking ~\scoop\apps\openssl1-light\current
'openssl1-light' was uninstalled.

Checklist:

• I have read the Contributing Guide.
• I have ensured that I am targeting the develop branch.
• I have updated the documentation accordingly.
• I have updated the tests accordingly.
• I have added an entry in the CHANGELOG.

[HUMORCE]

Operation of adding, deleting environment variable both no output, so a empty catch block here.